12.16.08
8th Grade Sample BFF Exam Questions
Here are a few sample BFF problems for the exam.
- Patty accelerate from a stop at 10 m/s2. How quick is she going after 5.5 seconds?
- Joe the Snail goes 45 m in 9 minutes. What is his velocity in m/s?
- Tom has a .5 kg ball. If he throws is with an initial velocity of 5 m/s what is its momentum?
- Judith is sky diving. She weight 45kg (with a weight of 441.5N). When she first jumps, what is her acceleration?
- Judith keeps falling. Now she feels a 200 N drag from air resistance. What is her new accelereation?
- Tyson the skateboarding bulldog has a mass of 15kg. If he is travelling with a momentum of 200 kg*m/s and acceleration of 2 m/s2, then what is his velocity?
- Tyson goes down a hill on a sled (no friction). It is 20 meters high. What would be his velocity at the bottom of the hill?
- Suppose he coasts for 5 seconds once he reaches the bottom. How far would he travel in that time
-Mr. K
December 16, 2008 at 1:56 pm
1. 55 m/s
2. 0.08 m/s
3. 2.5 kg m/s
4. 9.81 m/s2
5. 5.36 m/s2
6. 13.3 m/s
7. 19.81 m/s
8. about 99 meters
December 16, 2008 at 3:21 pm
Jake has two problems. See if you can find the errors.
-Mr. Kremer
December 16, 2008 at 6:53 pm
Wait, is that the answer key? Where’s the answer key?
December 16, 2008 at 7:11 pm
Mr. Kremer,
Could you list all of our BFFS on the website tonight?
December 16, 2008 at 8:10 pm
Very Confused…..
December 16, 2008 at 9:17 pm
Here are your BFFs,
v=d/t
a=v/t
F=ma
p=mv
p before = p after (momentum conserved)
TE1=TE2=TE3 (energy conserved)
GPE=mgh
KE=1/2mv^2
-Mr. K
December 16, 2008 at 9:22 pm
Here are the answers to the questions and the BFFs that I used to answer them.
1. a=v/t v=55 m/s
2. v=d/t v= .083 m/s
3. p=mv p=2.5 kg*m/s
4. F=ma a=-9.81 m/s2
5. F=ma a=-5.37 m/s2
6. p=mv v=13.3 m/s
7. GPE=mgh & KE=1/2mv2 v=19.81 m/s
8. v=d/t d=99.05 m
-Mr. K
(Jake forgot his negative signs.)
December 16, 2008 at 9:35 pm
Milla,
Ask a specific question and I will answer it. Which problem are you stuck on? The key is to pick the correct BFF, plug in what you know, and then use your mad algebra skills that Dr. B has given you.
-Mr. K
December 16, 2008 at 10:06 pm
Mr.Kremer,
I think I’m just overwhelmed and not thinking it through. When I looked at the problems I forgot all my BFFS and blanked out. UGH these finals are giving me brain problems.
But I am having trouble with Drag Problems, Kelvin to Celscius, Celscius to Kelvin, and the m/s and sec/hr.
December 16, 2008 at 10:12 pm
Milla,
The magic number for Kelvin to Celsius and the other way around is 273. You either add or subtract 273. Going from Celsius to Kelvin you add 273. When you go from Kelvin to Celsius you subtract 273.
The was I remember is:
* C -> K is up in the alphabet so you add
* K -> C is down in the alphabet so you subtract
-Mr. K
December 16, 2008 at 10:15 pm
1. 55 m/s
2. 0.8m/s
3. 2.5 kg m/s
4. -9.81m/s ^2
5. -5.37m/s^2
6. 13.3 m/s^2
7. 19.81 m/s
8. 99.05m
Thanks for the extra problems Mr. K.
-Lauren
December 16, 2008 at 10:29 pm
So if you had 150K=___C, would you do 273-150 or 150-273? And if you had 150C= ____K it would equal 423C?
December 16, 2008 at 10:37 pm
150K=(150-273)C
150C=(150+273)K
December 17, 2008 at 4:08 pm
These were the answers to the questions that I got but I’m not sure if they’re right:
1. 55 m/s
2. .8 m/s
3. p=2.5 kg m/s
4. 9.81 m/s^2
5. 5.36 m/s^2
6. 6.6 m/s
7. 19.8 m/s
8. 99 m
-Rachel
December 17, 2008 at 5:40 pm
Mr.K,
Do we need to know all of the bold words in each section? I’ve looked over the tests and none of the bolded words are on any of the tests.
What do you mean by key terms?
December 17, 2008 at 5:42 pm
Mr.K
Look on your email. Also, do we need to know friction?
Or the types of friction or how they differ?
Post the Answer!
Thanks
BrynnT
December 17, 2008 at 5:45 pm
Mr.K
Look on your email. Also, do we need to know friction?
Or the types of friction or how they differ?
Post the Answer!!
Thanks
BrynnT
December 17, 2008 at 6:01 pm
Hey Mr. K,
I get most of them, but in number two, i still dont get how you do the conversions. I know that they’re 60 seconds in a minute, but i dont really get where and how you plug them in and multiply them. Also, is number 7 a rollercoaster type problem?
If someone sees this before Mr. Kremer does, pleeeaaaaasssseeeeeee answer
Gracias,
Eli
December 17, 2008 at 6:20 pm
Yeah, I am really confused on converting km/hr to m/s and m/s to km/hr and
L/min to kL/hr. If anyone can explain how to do them in an easy way please answer.
- Mila
December 17, 2008 at 6:20 pm
oops i spelled my name wrong. i meant milla
December 17, 2008 at 6:21 pm
Mr.K
I was going through my test and I dont understand this problem so if you could explain it to me that would be great!
Tommy the chicken weighs 2kg and runs from Old MacDonaldsat 1. 5m/s for 45 seconds. What is his momentum during the escape?
If you could just post the answer by completing it on a post.
Thanks!
Brynn Tippit
December 17, 2008 at 6:26 pm
Mr.K
Do we need to know an example for the 2nd or 3rd law of motion.
Please Post!!
Thanks!
Brynn
December 17, 2008 at 6:57 pm
Elizabeth,
I think it one of those problems that he puts up after he does a sled problem. All the ones he showed us, were trying to figure out how far that person got in how ever much time. The first time he ever did one ,it was asking if, Ms.Grim’s mass is 35kg and she travels for 10sec, how far did she get… that kind of problem!
Brynn T
December 17, 2008 at 6:57 pm
Hey Milla,
i still dont get number two, but going from km/s and km/hr isn’t that bad. All you have to do is think about what units you need in your answer, then cancel out everything else. It’s hard to explain in writing, but if you call me, i’ll explain it to you
December 17, 2008 at 7:11 pm
Hey Eli,
I’m gunna call you. Thanks! Mil
December 17, 2008 at 7:13 pm
Mr.K
Do we need to know examples for SI units?
Post!!
Thanks
Brynn Tippit
December 17, 2008 at 7:52 pm
I get it now! Thanks Elisabeth!
December 17, 2008 at 8:08 pm
1.55M
2.0.2M/S
3. 2.5KG/M/S
4. 9.81M/S
5. 5.36 M/S
6. 13.3 M/S
7. 19.81 m/S
8 99.05 M
tell me the corrections i have to make
thanks,
Rusty
December 17, 2008 at 8:24 pm
yes we need to know the example of si units.
- milla
December 17, 2008 at 8:28 pm
Hey anyone out there, I still dont know how to do #2.
So if anyone can help, that be really nice!!!!!
December 17, 2008 at 8:35 pm
8th Graders!
The 6th comment shows the BFFs.
THe 7th comment shows the correct answers so you can check your own work! Jake’s first comment had the correct answers except for his +- signs on a few.
-Mr. K
December 17, 2008 at 8:36 pm
how are yall studying? what chapt.is free fall in??
anyone?
December 17, 2008 at 8:46 pm
Your not answering my questions… please answer them..anyone!!!!
Brynn T
December 17, 2008 at 8:55 pm
Hold your horses, Brynn. I was feeding my baby!
Brynn,
*Be able to give examples of Newton’s 1st and 3rd law.
*Newton’s 2nd law is the formula F=ma and you are demonstrating that to me through the calculations. So, examples wont be on the exam
*As for SI units, know the SI unit for the main quantities (temp, time, distance, volume, mass, …)
-Mr. K
December 17, 2008 at 8:56 pm
brynn i answered the one about the si units. its a few comments up
December 17, 2008 at 9:00 pm
Brynn,
“Tommy the chicken weighs 2kg and runs from Old MacDonalds at 1.5 m/s for 45 seconds. What is his momentum during the escape?”
BFF -> p=mv=2*1.5 = 3 kg*m/s
Don’t be distracted by the time.
-Mr. K
(Author’s note: that is how you spell Old MacDonald. I looked it up. No more guff from the peanut gallery!)
December 17, 2008 at 9:04 pm
BRYNN:
YES, YOU DO NEED TO KNOW WHAT IS FRICTION, TYPES, EXAMPLES
YOU DONT NEED TO KNOW EXAMPLES OF SI UNITS, BUT YOU NEED TO KNOW WHICH MEASUREMENTS YOU USE
LENGTH: METER
MASS: GRAM
TIME: SECONDS
TEMP: KELVIN
ENERGY: JOULES
WEIGHT/FORCE: NEWTON
VOLUME: LITER
YOU DONT NEED TO KNOW AN EXAMPLE OF THE 2ND LAW, BUT YOU DO NEED TO KNOW AN EXAMPLE OF FIRST & THIRD
HERE IS THIS ANSWER TO THIS PROBLEM YOU NEEDED HELP WITH
Tommy the chicken weighs 2kg and runs from Old MacDonald at 1. 5m/s for 45 seconds. What is his momentum during the escape?
1. YOU ARE TRYING TO SOLVE MOMENTUM, SO USE P=MV
2. WHAT YOU KNOW: P=?, M=2, V=1.5
3. PUT IN: P=2*1.5
4. THE ANSWER IS P=3 (KG M/S) > DONT FORGET UNITS
EMAIL ME IF YOU HAVE ANY OTHER QUESTIONS I’LL BE QUICKER TO RESPOND
HOPE I COULD HELP!
MILLA: FREE FALL IS ON PAGE 78 (CHAPTER 3-2)
-CATHERINE
December 17, 2008 at 9:05 pm
Mr. K,
So on the test if we put next to Newton’s 2nd Law f=ma, you will count that? Do you want a full description?
-Milla
December 17, 2008 at 9:06 pm
Jordan,
in the 2nd problem use the v=d/t formula. don’t forget that before dividing the distance by the time you need to multiply the time by 60 to convert it into seconds. also make sure that the 45 goes in the dividing box and the time outside of it.
-jennifer
December 17, 2008 at 9:07 pm
is the only difference between inellastic and elastic
is that ellastic bounces off after the collision
and inellastic the two objects stick togetheR?
December 17, 2008 at 9:08 pm
“I get most of them, but in number two, i still dont get how you do the conversions. I know that they’re 60 seconds in a minute, but i dont really get where and how you plug them in and multiply them.”
2. Joe the Snail goes 45 m in 9 minutes. What is his velocity in m/s?
convert 9 minutes into seconds 9*60=540 seconds.
then plug that into your bff 45/540 = .08m/s
“Also, is number 7 a rollercoaster type problem?”
Its pretty close. it is a sled problem. use KE to find the velocity at the bottom o the hill. use that to find out the distance traveled once it coasts.
-Mr. K
December 17, 2008 at 9:11 pm
Jennifer and Catherine,
Thank you for the explanations! Great Work. I love to see all of you using the blog so well.
As for elastic and inelastic, you got it!
-Mr. K
December 17, 2008 at 9:17 pm
to anyone,
can someone explain how to do the 6th problem?
-jennifer
December 17, 2008 at 9:18 pm
Why do we use the scientific method????
Thanks jen 4 the explination on #2!!!!!
December 17, 2008 at 9:19 pm
i know that #4 is 9.81m/s2 because that’s always the initial acceleration to earth, but how do you figure that out? or do you not even solve it…?
mr.k or anybody answer if you can
thanks
December 17, 2008 at 9:19 pm
hey Mr. K,
thanks i get it now and BRYNN look at our very first test fot the si units, but also make sure you know what each of them is measured in***
and CATHERINE yea i think that is the only diference, but also remember that the momentum is always conserved and if you’re doing an example on the test, make sure you take the objecs mass into consideration.
Hope i helped!!
Eli
December 17, 2008 at 9:19 pm
ANYONE,
Is anyone studying the other required stuff we need to know besides the bff problems?
December 17, 2008 at 9:20 pm
forget that last question i submitted, i get it now.
-jennifer
December 17, 2008 at 9:21 pm
BRYNN YOU SPELLED MY NAME WRONG!!!
and are you going in early for mrs. sarinana?
December 17, 2008 at 9:21 pm
For problem six you are using your momentum BFF p=mv. Don’t worryy about the information for acceleration he did that just to distract you. you set the problem up as 200=15v then divide both sides by 15 and your answer should be 13.3 m/s
Lauren
hope that helps
December 17, 2008 at 9:22 pm
#6
Tyson the skateboarding bulldog has a mass of 15kg. If he is travelling with a momentum of 200 kg*m/s and acceleration of 2 m/s2, then what is his velocity?
ignore the acceleration, you don’t need it
you don’t have enough info to use the velocity bff
so we’re gonna use p=mv
since p=200 and m=15, put them in….
200=15v
divide both sides by 15
the answer is 13.3333333333333333333…….. m/s (round it though)
December 17, 2008 at 9:24 pm
thanks elisabeth
milla i think other than the bffs, just the outline he gave us…
also liz made a study guide based on the topics we did
do you have it? or maybe you could ask her for it
December 17, 2008 at 9:25 pm
Jordan
The scientific method is a logical method or procedure used to answer a question.
-Mr. K
December 17, 2008 at 9:26 pm
hey CATHERINE,
could you send liz’s outline to me over e-mail? or is it just a print out?
i’ve done one myself but haven’t finished it yet. I am so scared for this final!!
December 17, 2008 at 9:27 pm
Hey I have Liz’s thing but it is printed out you can see it tomorrow. it is basically just the outline Mr. K gave us.
Lauren
December 17, 2008 at 9:28 pm
i only have a print out version sorry milla!
dont worry you will do fine
but you will have to ask liz for the guide, i dont have it
but you can look at it tomorrow if you want
December 17, 2008 at 9:29 pm
Thanks Mr. K!!!!!!!!!
I was looking trough my notes and I found some on all the different
graphs like pie and bar graph. Do we need to know anything about that???
December 17, 2008 at 9:30 pm
Whats position
December 17, 2008 at 9:30 pm
THANKS LAUREN and CATHERINE,
If I could look over it tomorrow that would be great.
December 17, 2008 at 9:31 pm
Hey yall,
can somebody help me with the 7th BFF problem? I still dont really get it
-Eli
December 17, 2008 at 9:31 pm
WAIT WHAT ARE THE COLLISION PROBLEMS?
AN EXAMPLE???
December 17, 2008 at 9:35 pm
i dont get number six
December 17, 2008 at 9:37 pm
Mr. K,
Do we need to know independent and dependent variables and are we going to have to identify simple machines in a compound machine.
LS
December 17, 2008 at 9:37 pm
I did both sets of problems and got them right.=^I
December 17, 2008 at 9:38 pm
LAUREN i think position is just where you are… the book doesnt have it as a definition
MR. K will we have to know position?
JORDAN i don think we need to know that…it’s not on the outline….unless you are talking about position graphs
ELISABETH hang on and i will solve #7
MILLA: all you need to know about collisions is that elastic bounces off and inelastic sticks after the collision, BUT the both have the same momentum (law of conservation) i dont think you need to know an example, sorry i dont have one anyway
December 17, 2008 at 9:40 pm
Hey JakeFox your tiger icon is awesome
December 17, 2008 at 9:41 pm
Hey jordan i think??
Lauren asked if we need to know pie charts and stuff and we dont so no worries about that
))
-EU
December 17, 2008 at 9:41 pm
Brock on #7 i know your velocity is 5.3555555 m/s, what about acceleration??? same thing? i am so confused… i used the BFF for velocity… is that right?
December 17, 2008 at 9:41 pm
Elisabeth
for the 7th BFF problem, first find the the GPE at 20m when the sled is not yet in motion and the KE is 0. to find the velocity set the problem equal to the GPE you just solved for because it is the total energy in the problem. you will have no GPE at the bottom of the hill because the sled is in motion. Solve for the velocity using the KE=1/2mv2 formula.
i hope that wasn’t too confusing
-jennifer
December 17, 2008 at 9:41 pm
Thanks CATHERINE
could someone explain sliding, rolling, and static friction?
THANKS< MILLA
December 17, 2008 at 9:42 pm
Thanks Kit-Kat!!!!!!
Um…. could u explain what a derived SI unit is???????
December 17, 2008 at 9:43 pm
wait so jennifer that means the velocity is zero?????? i couldnt figure it out!
(on #7)
December 17, 2008 at 9:44 pm
Thanks Catherine
December 17, 2008 at 9:46 pm
Free Fall, Terminal Velocity?????
December 17, 2008 at 9:46 pm
By the way that was Zack who typed about Jake and Mr. K, could you please define position.
Lauren
December 17, 2008 at 9:46 pm
catherine,
Total energy (2943)= 1/2 of the mass (7.5) * v2
-jennifer
December 17, 2008 at 9:47 pm
MILLA:
(these are my definitions, not the book’s)
STATIC: whenever there is friction on an object that’s making it NOT MOVE… because there’s too much friction opposing your motion (basically it’s not sliding/rolling…)
SLIDING: the friction when two objects rub
ROLLING: the friction of anything rolling, basically
PS does the first def make sense?
December 17, 2008 at 9:48 pm
Milla,
free fall: when the only forces acting upon an object are gravity and air resistance
you will have to look up terminal velocity.
-jennifer
December 17, 2008 at 9:50 pm
CATHERINE
I am not sure….Could you re-explain?? I don’t get the definitions.
December 17, 2008 at 9:50 pm
Milla…
TERMINAL V- when a falling obj. can’t speed up any more
Does that make sense????
December 17, 2008 at 9:50 pm
if there’s a set limit on how many comments can be posted under one section, then there isn’t going to be much more room.
-jennifer
December 17, 2008 at 9:50 pm
jennifer, the answer is
the square root of 392.4?????
(my calculator doesnt have the magic button)
is that right?
and how did you figure out the total again? (sorry!)
December 17, 2008 at 9:51 pm
Yes, that makes sense. Thanks JA JA.
December 17, 2008 at 9:53 pm
MILLA:
static: friction of a NONmoving object
sliding: friction of two objects rubbing against
rolling: friction between rolling obj (EX: wheel) and ground
does that make more sense?
sorry last time it was worded weirdly
December 17, 2008 at 9:53 pm
Catherine,
the square root of 392.4 is 19.81 and yes you are right.
To find the TE add the KE and PE
15*9.81*20=2943
no KE when the sled is not in motion so 2943 is the TE.
December 17, 2008 at 9:54 pm
Millos,
Terminal velocity is when when gravity=air resistance. If an object is larger, it takes longer to reach it’s TV, but if it wighs les,, it takes a shorter amount of time…
Hope it helped!!
Eli
December 17, 2008 at 9:56 pm
oh yeah i knew that sorry but thanks jennifer
jordan i dont know if someone has already answered this, but a derived unit is combined,
EXAMPLES:
m/s
mph
(and also those ones we had trouble with, like) km/min, kg/sec…weird ones
December 17, 2008 at 9:59 pm
What exasctly do we need 2 know 4 collisions?
just that elastic is when the bounce apart and inelastic is when the stick
together? O r what?
December 17, 2008 at 9:59 pm
THANKS GUYS…. BUT ANOTHER QUESTION.
COULD SOMEONE EXPLAIN #2, and #5. And why is #4 negative?? I got the answer but when i checked it it said it was negative…..ugh im gunna fail.
December 17, 2008 at 10:04 pm
JORDAN
all you need to know about collisions is that elastic bounces off and inelastic sticks after the collision, BUT the both have the same momentum (law of conservation) i dont think you need to know an example, sorry i dont have one anyway
MILLA
you are not going to fail… its only 9:00 theres still time to study
when you solve #4, you are right it’s NOT negative, but you have to add it on after because since she’s skydiving, she’s going DOWN, the neg. just tells direction
jennifer explained #2 somewhere up there, and im about to do #5
December 17, 2008 at 10:06 pm
Milla,
if you scroll up a ways i answered #2 for someone else
#3 use the p=mv formula
#4 is negative because gravity is pulling down
-jennifer
December 17, 2008 at 10:08 pm
Thanks Catherine. ill look up jen’s right now
December 17, 2008 at 10:08 pm
Milla, deep breath u’ll do fine….
#2-I’m confused on that one too
#5-the force she feels on gravity pulling her (DOWN!!!!! so it’s NEGATIVE!)
The gravitational force is -441.5+200= -241.5, now put it in to the equation F=MxA -241.5=45A now divide both sides by 45 and u get -48.3
December 17, 2008 at 10:09 pm
milla, here’s number 5
5. Judith keeps falling. Now she feels a 200 N drag from air resistance. What is her new accelereation?
use F=MA, because you can fill in that
all your forces are -200n and -441N (from the last problem, it’s related)
and judith has a mass of 45kg
-200-441=45a
1. combine -200 and -441
-641n=45a
2. divide both by 45
-14.24444444444444444…. rounded to -14.24m/s2
*****or you can just add the negative afterwards, instead of using it throughout the problem,
but remember if the person is going down/falling, its negative
December 17, 2008 at 10:09 pm
Milla, for the friction, you need to know static but instead of rolling and sliding, they both fit under the category of kinetic friction. there is static non moving and kinetic friction moving.
LS
December 17, 2008 at 10:09 pm
HI GUYS, JUST TO LET YALL KNOW, THAT IF YOU SAY THAT YOUR ARE GUNNA FAIL, YOU WILL FAIL, MILLA. SO THE POINT IS TO STAY POSITIVE.
December 17, 2008 at 10:10 pm
yeah, stay positive
December 17, 2008 at 10:10 pm
On 2 you just use velocity formula but you first convert minutes to seconds so times by 60 which gives you 540. then 9 divided by 540 gives you your answer.
LS
December 17, 2008 at 10:13 pm
for the second one i did
v=d/t
9*60= 540
v= 45/540
v= 0.083m/s??
December 17, 2008 at 10:13 pm
mr.kremer
if you’re still there
can i have another of the unit conversion, where the unit is a fraction
thanks
December 17, 2008 at 10:14 pm
THATS RIGHT MILLA
December 17, 2008 at 10:15 pm
Lauren,
in the 2nd problem u do 45 divided by 540 to get 0.08
-jennifer
December 17, 2008 at 10:15 pm
W only have to know 4 things for a position time graph right
December 17, 2008 at 10:16 pm
we’re at over a 100 comments, Mr. Kremer should be proud!
-jennifer
December 17, 2008 at 10:17 pm
I meant that. I got the answer wrong just typed it wrong sorry
December 17, 2008 at 10:19 pm
Yeah us over 100 coments!!!! Hey were is Mr. Kremer??????
December 17, 2008 at 10:20 pm
What is a derived unit????
And Mr. K (were ever u r) please put more problems like #2, caz I don’t really get it
December 17, 2008 at 10:20 pm
POSITION GRAPHS:
TELLL ABOUT
1. INITIAL POSITION: at/near/far from…origin
2. VELOCITY: constant or not constant, +/-, fast or slow
3. ACCELERATION: acc or not
thats 5 things i think, unless we dont need one of them
December 17, 2008 at 10:21 pm
what’s the answer to
10km/h=_____m/s
3000m/s=_____km/h
20km/h=_____m/s
15L/min=_____kL/hr
please respond if u know the answer!
-jennifer
December 17, 2008 at 10:22 pm
hey is #7 98.09088m/s????
December 17, 2008 at 10:24 pm
jordan this isnt a good def but
a derived unit is two units combined to make one unit,
EXAMPLES:
m/s
mph
(and also those ones we had trouble with, like) km/min, kg/sec…weird ones
FOR A BETTER DEF. LOOK ON PAGE 19 OF OUR BOOK
MR.K IS PROBALY HELPING 7TH GRADE
December 17, 2008 at 10:24 pm
JEN:
10km/h= 2.78m/s
3000m/s=1080km/h
20km/h=5.6m/s
15L/min=.9kL/hr
December 17, 2008 at 10:26 pm
does anyone if im right? look 3 comments up?
December 17, 2008 at 10:26 pm
Thanks Catherine
Jordan, a derived unit is a combination of SI units like m/s
Jen,
1. 2.78
2. 10,800 km/h
3. 5.56m/s
4. .9 kL/hr
December 17, 2008 at 10:27 pm
Sorry Milla no
December 17, 2008 at 10:27 pm
Hey Milla!!!!!!!!!!!!! You got it right!!!!!!!!!!!!!!
C u r not gonna fail!!!!!!!!
December 17, 2008 at 10:28 pm
Milla,
i got 99.05 but close enough, also can you explain how you got the answers to the km/h to m/s if it’s possible?
-jennifer
December 17, 2008 at 10:28 pm
its 19.81
December 17, 2008 at 10:28 pm
Wait what? Lauren why did you say “Sorry Milla No”???
December 17, 2008 at 10:29 pm
Great Posting 8th graders!
I love the questions and the moral support. Lauren and Jordan, you don’t need to veer so far off the outline. While we discussed position, pie charts vs. line graphs, and indep/depend variables, you don’t need to know about them in any way not on the outline. Use your outline as a guide.
-Mr. K
December 17, 2008 at 10:29 pm
Wait….. Milla on #7 did u mean 19.81 not 9.81
December 17, 2008 at 10:29 pm
whoops! 99.05 is the answer to number 8 not 7
December 17, 2008 at 10:32 pm
7 is 19.81
December 17, 2008 at 10:34 pm
FOR NUMBER 8,
WOULD YOU SET IT UP LIKE
19.8=D/5
I DID THAT AND GOT 99.05 METERS
AM I RIGHT?
December 17, 2008 at 10:35 pm
GOOD LUCK YALL!!!!!!!!!!!
I think im gonna go to slepp so i cant post anymore
((((
BYE!!!!
-ELI
December 17, 2008 at 10:35 pm
You are right Catherine
December 17, 2008 at 10:36 pm
JEN:
10km/hr= hr/3600sec+1000m/1km= 2.78m/s
okay first you want to cancel out the hours so you out hours on top. Then, since you know that you are trying to solve for how many meters per SECOND equals 10km/hr, you write down how many seconds are in 1 hour; 3600. So far you have 1hour over 3600seconds. Then, you are trying to cancel out km so you put km on bottom and since you are trying to solve for how many METERS per second equal 10km/hr, you know that 1000 meters are in one kilogram so now you have:
10km/hr= 1hr/3600sec+1000m/1km
Now you multiply 10*1000 divided by 3600 and you get….. 2.78m/s!!!
December 17, 2008 at 10:36 pm
YAY THANKS LAUREN
December 17, 2008 at 10:37 pm
I GIVE CREDIT TO ELISABETH FOR HELPING ME UNDERSTAND WHAT I JUST SENT JEN.
December 17, 2008 at 10:37 pm
Milla,
for 10km/h=________m/s
i got .278
December 17, 2008 at 10:39 pm
oh and thanks for the help milla
-jennifer
December 17, 2008 at 10:39 pm
all you did is forget one 0 when you were multiplying. You’ve got it.
I did that the first time too.
December 17, 2008 at 10:40 pm
wait lauren why did you say SORRY MILLA NO? what did i get wrong?
December 17, 2008 at 10:42 pm
wait is 1.5hr= 90seconds?
December 17, 2008 at 10:43 pm
Ya
December 17, 2008 at 10:43 pm
I’m going to sleep. See everyone tomorrow at school!
-jennifer
December 17, 2008 at 10:45 pm
whats position…anyone who is still awake
December 17, 2008 at 10:48 pm
POP QUIZ!!!
(take this to see what you need to study)
(but its only 10 questions so not everything is on it)
1. name five types of energy and give examples.
2. what are the types of friction?
3. A frog weighs 5kg and runs (hops) at 3 m/s away from mrs. carrola, for one minute starting at 3:25 pm. what is it’s momentum?
4. name newton’s 3 laws
5. what is the law of conservation of energy?
6. _____K = 125 C
7. _____mg = 2354g
8. why do we use simple machines?
9. what is the law of conservation of energy?
10. DEFINE velocity, and what is the BFF for it?
if you want to take it, answer as many as you can and post answers!
-CATHERINE
December 17, 2008 at 10:49 pm
position is where you are, in life or on a graph
but i dont think we need to know it
sorry i was making the quiz
if you wan t to take it
i’ll grade you
December 17, 2008 at 10:49 pm
i am not 100% sure about position
December 17, 2008 at 10:50 pm
yeah ill take it!! hold on
December 17, 2008 at 10:51 pm
sure
good luck
December 17, 2008 at 10:54 pm
Do we only need to know the different types of energy to label an example?
-Enrique
December 17, 2008 at 11:00 pm
i dont get what your saying enrique, but we do need to know examples for the test, and types of energy
December 17, 2008 at 11:00 pm
1. Kinetic- a car moving on a road
Potential- a ball about to be dropped
Thermal- a lightbulb warming me
Electricial- an oven turned on
Nuclear- the sun
2. Sliding, Rolling, Static Friction
3. 15kgm/s
4. 1st Law- An object in motion will stay in motion and an object at rest will stay at rest until acted upon an object
2nd law- f=ma
3rd law- for every action theres an equal and opposite reaction
5. No energy is gained nor lost. it stays the same
6. -148C
7.2354000mg
8. IDK
9. you already asked that question on #5
10. IDK SPEED IN A DIRECTION? v=d/t
December 17, 2008 at 11:01 pm
ok milla im gonna grade it starting now
it may take a minute or two
December 17, 2008 at 11:02 pm
okay. i g2g soon to take a shower and study more so….
December 17, 2008 at 11:06 pm
1. correct, but you may want to say GRAVITATIONAL potential
2. correct
3. correct
4. correct…..well…until met by a force, not an object…… i think mr.k would take off points for that but im not going to
5. correct
6. NO, i’ll explain it in the next post
7. correct
8. BLANK, i’ll explain it in the next post
9. oh yeah sorry that 5 and 9 are the same
10. correct!
TOTAL WRONG: 2 (6&8)
GRADE: 80
December 17, 2008 at 11:07 pm
ok then ill just say the ones you got wrong real fast
6. K = C+273
K=125+273
K=398
8. to make work easier
see you tomorrow
bye, if there’s anyone else left!
December 17, 2008 at 11:08 pm
okay can you explain the ones i got wrong??
December 17, 2008 at 11:10 pm
Kit-Kat nice pop quizz!:-) Am i correct?
#1: GPE- apple on a tree
KE- Moving car
Thermal- Fire
Chemical PE- Coal
Elastic PE- a rubberband
#2: Static-non moving friction
Rolling/Sliding-moving friction
#3: 15
#4: 1- an obj. in motion tends to stay in motion, and an obj at rest
tends to stay at rest
2- F=MxA
3- Every action there is an equal and opposite reaction
#5: Energy is never lost or created- TE=TE
#6: 398k
#7: 234000mg
#8: Why do we use simple Machines?
#9: You all ready asked that
#10Velocity-speed in a direction V=d/t
December 17, 2008 at 11:11 pm
Anyone still up
December 17, 2008 at 11:14 pm
yeah im up
December 17, 2008 at 11:14 pm
what are all the 11 answers to the conversions? could one of yall give them to me?>
December 17, 2008 at 11:16 pm
milla…..look up
lauren…….im up but im may not be on the com. for that much longer
jordan………….about to grade you
December 17, 2008 at 11:17 pm
good job jordan 100%
December 17, 2008 at 11:17 pm
barely… distance from origin or where an object is on a graph…… im sleeeeppppyyyy
-eli
December 17, 2008 at 11:18 pm
ok cool, yeah im about to go upstairs and study but away from the computer so any last minute questions before i go.
December 17, 2008 at 11:18 pm
what conversions are you talking about milla?
December 17, 2008 at 11:20 pm
the conversions that he posted on the blog just look….PLEASE SOMEONE
no one is responding to me……lauren are you there. …..help me
December 17, 2008 at 11:20 pm
Hey anyone left what is position??????
December 17, 2008 at 11:21 pm
I guess thats a no, so Ill talk to you all tomorrow at school. you all will all do great thanks for the help everyone and Mr. K.
LS
December 17, 2008 at 11:23 pm
ok i g2g i guess. maybe will come back idk.
c yall tomorrow
December 17, 2008 at 11:23 pm
Hey who ever is left!!!! What is position and Direction!?!?!?!?!?!!?
December 17, 2008 at 11:23 pm
yeah what is direction? a
December 17, 2008 at 11:28 pm
i dont know what direction is but ill email mr.k
guys, i have told you what position is a million times!!!!!!!!
press control and F and type in position
or click edit, find, type position, press enter
is it jordan and milla thats still there?
sorry but i dont have the answers to the conversions
it may take me a few min. to respond, and i may leave
but dont freak out, ok?
December 17, 2008 at 11:29 pm
emailing mr.k
anyone there?
or am i by myself……lol
December 17, 2008 at 11:31 pm
No ur not alone yet!!!! But i need to get to bed soon
December 17, 2008 at 11:34 pm
ok im about to leave
i was just wondering if you figured out with direction is yet?
December 17, 2008 at 11:35 pm
Please no freaking out. You all should go to sleep now so you aren’t brain-dead tomorrow.
You dont need a scientific definition of direction. You are overthinking.
Good Luck and Good Night!
-Mr. K
December 17, 2008 at 11:35 pm
nighty-night
December 17, 2008 at 11:36 pm
Night!!!!!!!!:-) Thanks 4 the help night!!!
January 13, 2009 at 9:14 pm
WOW!!! YAll wrote ALOT!! HAHA 7th grade only wrote 78 comments.
LOL,
Natalie