Quick question regarding the test. Number 42 asks us to calculate the kinetic energy of an object. I thought I did the calculation correctly (1/2 mass*velocity squared) but my answer is not on the list. Does anyone else share this problem? -Kevin Meglathery
If you are unable to answer that question, I have another. Question 30 asks us about the efficiency of a normal car engine. I seem to recall Mr. Crane telling us an answer that is not on the list. That answer is conviniently in the middle of two of the options, so I can't go with the closer one. Any suggestions? -Kevin Meglathery
I believe that we are to discuss the table of contents in our notebooks here... I will start with the concept of my potty chart. We gotta start somewhere. I believe all that it involved was identifying maximums and minimums, as well as means, medians, and maybe even modes.
I think your potty chart was to teach us how to analzye data in the simplest manner. If one part of a graph is radically different from another, then we should be able to notice it and give a possible explanation (like Taco Tuesday as an explanation for Tuesday's higher number of stickers). -Kevin Meglathery
The most important idea from Richie's Potty Chart, as you guys mentioned, was minimums and maximums. Even now, with kinetic and potential energy, we're still looking to find the minimums and maximums and how they compare to other pieces of data.
Guys there is most likely going to be at least one big P.U.K.E question on the Final, so it would be good to look over that as one of the main things this year.
Mr. Crane said there were no open ended questions on the final, but you'll definitely need to know how to do PUKES because that's how you can solve every physics problem.
I would go back and study the things Mr.Crane told us to star in our notebooks, the stuff he said to write in the back like laws and equations, and anything else that we covered for more than one day. ~Gianna Briglia
17. A 10-kg brick and a 1-kg book are dropped in a vacuum. The force of gravity on the 10-kg brick is a. 10 times as much as the force on the 1-kg book. b. zero. c. the same as the force on the 1-kg book. ANSWER: A
Please help explain. I thought that it would be C. -Kevin Meglathery
You see, the accelerations are the same, and to keep that property, the force on the larger object must be higher then the smaller object. It is asking force, not acceleration.
Oh yeah, I remember now. Mr. Crane was explaining that if that wasn't true, the brick's mass would act against it and make it fall slower. Thank you for clearing that up. -Kevin Meglathery
Lightning moves at 180,000 miles per second. Thunder is about 2 (700 miles per hour.) Factor label takes the fascination out of everything. -Kevin Meglathery
What matters is that you are not accelerating it after you get it moving. Without acceleration, you are doing no work because W=m*a*D. If you were to move it vertically, it would be doing work because there is an unbalanced force and therefore it accelerates.
John an object with kinetic energy could be traveling at a constant speed. Regardless of the movement, as long as the object is MOVING there will be momentum and KE -Taylor Nardone
A push on a 1-kilogram brick accelerates the brick. Neglecting friction, to equally accelerate a 10-kilogram brick, one would have to push __________. A) with 100 times as much force. B) with just as much force. C) with 10 times as much force. D) with one tenth the amount of force.
Can someone help me with this? I think its C but online it says A. I'm not sure if the online answer makes sense because f/m=a so for a hypothetical 1N/1kg = 1m/s^2 so you need 10N/10kg to equal 1 m/s^2. is this right? -Mark Pino (I don't have crane but D'amore doesn't have a blog)
This might be a little late, but I think you're right. If the forces were the same, then the larger brick would move at 1/10 the smaller brick's acceleration. In order to have the same acceleration, the force would need to be ten times greater. -Kevin Meglathery
A ball tossed vertically upward rises, reaches its highest point, and then falls back to its starting point. During this time the acceleration of the ball is always
a. in the direction of motion.
b. opposite its velocity.
c. directed downward.
d. directed upward.
could some one please explain this to me. I know the answerer is c.
when the ball is in your hand, the forces are balanced. However, when it leaves your hand, there is only one force causing it to only go in one direction. In this case, it is going up because that was the direction of the motion, but the only force acting is gravity. It is going downward in this case because gravity is always directed down to towards the center of the earth.
Do you mean percent error? I'm pretty sure it's the expected value minus the value you got divided by the expected, all times 100. [(Expected)-(Actual)/(Expected)]*100. -Kevin Meglathery
I don't understand this question i keep getting 360 J. "How much work is done on a 60-N box of books that you carry horizontally across a 6-m room?" work=maD ma=60N D= 6
That one is sort of a trick question. Work is done when you have to exert a force against another one. That's why lifting things requires work; you are fighting against gravity. But as soon as you stop raising it, the forces balance out, and no work is being done. When you carry things across a room, there is no force to overcome, and you end up doing no work. It's just like the story Mr. Crane told us when he had to move a Jacuzzi with the "help" of otherse. -Kevin Meglathery
Is there supposed to be a test available here or no?
ReplyDeleteI think it will probably be something to help with the final.
DeleteI know this is a little late, but there is a review test here now.
DeleteI think so. He may have forgot.
ReplyDeleteTy Coffey
So do we have any test due by tomorrow?
ReplyDeleteron, the test is due monday night. the calendar says so
ReplyDeleteron, the test is due monday night. the calendar says so
ReplyDeleteThe test is further down on the feed and it is due tomorrow night
ReplyDeleteTaylor Nardone
ReplyDeleteQuick question regarding the test. Number 42 asks us to calculate the kinetic energy of an object. I thought I did the calculation correctly (1/2 mass*velocity squared) but my answer is not on the list. Does anyone else share this problem?
ReplyDelete-Kevin Meglathery
Try finding the answer backwards?
DeleteGo through all of the choices and find the knowns to see if they match.
Kevin, Newtons is mass and acceleration. You need to divide by 10 to remove acceleration, then you will have your mass to plug into the formula
DeleteOh...that makes sense now. Thank you for clearing that up.
Delete-Kevin Meglathery
If you are unable to answer that question, I have another. Question 30 asks us about the efficiency of a normal car engine. I seem to recall Mr. Crane telling us an answer that is not on the list. That answer is conviniently in the middle of two of the options, so I can't go with the closer one. Any suggestions?
ReplyDelete-Kevin Meglathery
I got the same problem, yahoo right? I went with the higher one...but I feel like the lower one is more...encouraged.
DeletePretty sure the answer is 30% for that one. Asked an AP physics student about it.
DeleteIt's weird, she said she learned it in biology class the year before.
DeleteI believe that we are to discuss the table of contents in our notebooks here... I will start with the concept of my potty chart. We gotta start somewhere. I believe all that it involved was identifying maximums and minimums, as well as means, medians, and maybe even modes.
ReplyDeleteI think your potty chart was to teach us how to analzye data in the simplest manner. If one part of a graph is radically different from another, then we should be able to notice it and give a possible explanation (like Taco Tuesday as an explanation for Tuesday's higher number of stickers).
Delete-Kevin Meglathery
The potty char I believe was to tech us not only maxes and mins, but patterns and reasoning in general.
DeleteThe most important idea from Richie's Potty Chart, as you guys mentioned, was minimums and maximums. Even now, with kinetic and potential energy, we're still looking to find the minimums and maximums and how they compare to other pieces of data.
DeleteThe midterm review is still on the blog so that will help for the begining of the yer.
ReplyDeleteGuys there is most likely going to be at least one big P.U.K.E question on the Final, so it would be good to look over that as one of the main things this year.
ReplyDeleteMr. Crane said there were no open ended questions on the final, but you'll definitely need to know how to do PUKES because that's how you can solve every physics problem.
DeleteI would go back and study the things Mr.Crane told us to star in our notebooks, the stuff he said to write in the back like laws and equations, and anything else that we covered for more than one day.
ReplyDelete~Gianna Briglia
The study guide he put up is not working for me. It says page not found. Anyone else having trouble with this?
ReplyDeleteyeah I am too
Delete"Error 404" if that means anything to people with computer knowledge.
Delete-Kevin Meglathery
17. A 10-kg brick and a 1-kg book are dropped in a vacuum. The force of gravity on the 10-kg brick is
ReplyDeletea. 10 times as much as the force on the 1-kg book.
b. zero.
c. the same as the force on the 1-kg book.
ANSWER: A
Please help explain. I thought that it would be C.
-Kevin Meglathery
I think that might be a mistake because the answer should be C. There is no way it would be ten times more. That is like saying gravity = 100m/s^2.
DeleteYou see, the accelerations are the same, and to keep that property, the force on the larger object must be higher then the smaller object. It is asking force, not acceleration.
DeleteThat makes sense. I assumed it was acceleration.
DeleteOh yeah, I remember now. Mr. Crane was explaining that if that wasn't true, the brick's mass would act against it and make it fall slower. Thank you for clearing that up.
Delete-Kevin Meglathery
I still find it fascinating about the time it takes for the lighting to be seen compared to the thunder. Pretty incredible.
ReplyDeleteLightning moves at 180,000 miles per second.
DeleteThunder is about 2 (700 miles per hour.)
Factor label takes the fascination out of everything.
-Kevin Meglathery
It's boring in terms of numbers, but in an actual experiment, it really is intriguing. No factor labels needed there.
DeleteHow much work is done on a 60-N box of books that you carry horizontally across a 6-m room?
ReplyDeletea. 0 J
b. 6 J
c. 10 J
d. 60 J
e. 360 J
ANSWER: A
I understand why the answer is A here, but depending on where you hold the box, could the answer change?
What matters is that you are not accelerating it after you get it moving. Without acceleration, you are doing no work because W=m*a*D. If you were to move it vertically, it would be doing work because there is an unbalanced force and therefore it accelerates.
DeleteThank you Billy. That answered my question.
Delete
ReplyDeleteIf an object has kinetic energy, then it also must have
a. impulse.
b. force.
c. momentum.
d. acceleration.
e. none of the above
ANSWER: C
I thought the answer was D. Wouldn't KE have to have acceleration in it?
John an object with kinetic energy could be traveling at a constant speed. Regardless of the movement, as long as the object is MOVING there will be momentum and KE
Delete-Taylor Nardone
If it had acceleration the KE would change. If an object was already moving it has KE regardless , even if it has no acceleration.
ReplyDeleteIn PE= mgh ...... g stands for gravity right?
ReplyDelete~Taylor Nardone
Yes. Gravity makes you do work to increase the height, therefore giving the object itself potential energy.
Delete-Kevin Meglathery
Disculpe sire crane
ReplyDeleteCan we put the units that each thing is measured in on our formula sheets
Taylor N.
I believe we can. To my understanding, we are allowed to include
DeleteEquations
Variables
Parent graphs
That's all I can remember.
-Kevin Meglathery
but does that include units
DeleteTdones
Maybe. I'm not entirely sure.
Delete-Kevin Meglathery
Yes, you are allowed to do that.
DeleteDid Mr. Crane say we could put conversions on formula sheet?
ReplyDelete-Katie Cabrera
I don't know Katie, but i think it was just equations
DeleteA push on a 1-kilogram brick accelerates the brick. Neglecting friction, to equally accelerate a 10-kilogram brick, one would have to push __________.
ReplyDeleteA) with 100 times as much force.
B) with just as much force.
C) with 10 times as much force.
D) with one tenth the amount of force.
Can someone help me with this? I think its C but online it says A. I'm not sure if the online answer makes sense because f/m=a so for a hypothetical 1N/1kg = 1m/s^2 so you need 10N/10kg to equal 1 m/s^2. is this right?
-Mark Pino (I don't have crane but D'amore doesn't have a blog)
This might be a little late, but I think you're right.
ReplyDeleteIf the forces were the same, then the larger brick would move at 1/10 the smaller brick's acceleration. In order to have the same acceleration, the force would need to be ten times greater.
-Kevin Meglathery
how would you solve this...
ReplyDeleteHow much does a 3.0-kg bag of bolts weigh?
Weight is a force; to get force, you multiply mass and acceleration. In this case, you would multiply 3 by 9.8 (or 10).
Delete-Kevin Meglathery
that makes perfect sense I didn't think of it that way.
Delete
ReplyDelete2.
A ball tossed vertically upward rises, reaches its highest point, and then falls back to its starting point. During this time the acceleration of the ball is always
a.
in the direction of motion.
b.
opposite its velocity.
c.
directed downward.
d.
directed upward.
could some one please explain this to me. I know the answerer is c.
acceleration is gravity. gravity is always 9.8 and directed downwards.
DeleteAs soon as the ball leaves your hand, the only force acting on it is gravity. Gravity will always be accelerating objects downwards.
Delete-Kevin Meglathery
when the ball is in your hand, the forces are balanced. However, when it leaves your hand, there is only one force causing it to only go in one direction. In this case, it is going up because that was the direction of the motion, but the only force acting is gravity. It is going downward in this case because gravity is always directed down to towards the center of the earth.
DeleteOk I get it now.
ReplyDeleteWhat is the percent formula equation?
ReplyDeleteDo you mean percent error?
DeleteI'm pretty sure it's the expected value minus the value you got divided by the expected, all times 100.
[(Expected)-(Actual)/(Expected)]*100.
-Kevin Meglathery
Can someone explain to me how to find a joule? (with an equation)
ReplyDeleteJoules measure work. Work can be derived from the equation
DeleteWork=Force*Displacement(distance).
So a joule equals one "Newton-meter."
-Kevin Meglathery
Oh ya I forgot it was the unit for work, thanks Kevin.
DeleteI don't understand this question i keep getting 360 J. "How much work is done on a 60-N box of books that you carry horizontally across a 6-m room?" work=maD ma=60N
DeleteD= 6
That one is sort of a trick question. Work is done when you have to exert a force against another one. That's why lifting things requires work; you are fighting against gravity. But as soon as you stop raising it, the forces balance out, and no work is being done. When you carry things across a room, there is no force to overcome, and you end up doing no work. It's just like the story Mr. Crane told us when he had to move a Jacuzzi with the "help" of otherse.
Delete-Kevin Meglathery