Phreshman Momentum
HW Problems 1-5
Note y=5m/s
Objectives
After studying the material of this chapter, you should be able to:1. Define linear momentum and write the mathematical formula for linear momentum from memory.
2. Distinguish between the unit of force and momentum.
3. Write Newton's Second Law of Motion in terms of momentum.
4. Define impulse and write the equation that connects impulse and momentum.
5. State the Law of Conservation of Momentum and write, in vector form, the law for a system involving two or more point masses.
6. Distinguish between a perfectly elastic collision and a completely inelastic collision.
7. Apply the laws of conservation of momentum and energy to problems involving collisions between two point masses.
This is going to sound like a strange question, but does anyone else see a very large white rectangle on this post?
ReplyDelete-Kevin Meglathery
I was thinking the same exact thing.
DeleteOh, now it is unavailable. http://i.imgur.com/iyMWMDq.png
DeleteMine has a little puzzle piece.
DeleteMine is a large black rectangle
ReplyDelete-Robyn
That's what mine is like too.
Delete-Skylar Young
Im not really sure how to get to the questions... Am I missing something?
ReplyDelete-Catherine Samara
I think we just have to know the answer the objectives.
Delete-Skylar Young
I can't even see any questions. Just a box that I can scroll over. Nothing inside.
ReplyDelete-Jake Naumann
There are no questions. Just information on Newton's Cradle and an application allowing you to experiment with Newton's Cradle.
DeleteIt is really cool!
DeleteCan you see the objectives?
Delete-Skylar Young
When I went back to this post this morning, it said something about needing Java. Even though I didn't change anything, now I can see inside it, but the text is almost the same color as the background. I think there are supposed to be pictures in it, but I can't see them at the moment.
ReplyDelete-Kevin Meglathery
It just crashed java. Yay.
DeleteI am getting the same thing...having a hard time seeing what the questions are. It says error.
ReplyDeleteIf anyone has just an empty box, try updating your java, if that still doesn't work, then try a better web browser.
ReplyDeleteIf none of that works, then ask Mr. Crane,
DeleteFor those of you without access to it: http://i.imgur.com/tSSeXvQ.png
It is a newton's cradle simulator.
If you are talking about what he wrote up top it's things we should know how to define/calculate and know about newtons laws and especially momentum -Alexis Dearborn
ReplyDeleteDo you know if we need to copy this down for class or is it just something we look at and know how to do. I know this question has been asked a lot.
Delete-Catherine Samara
We probably don't need to write anything down. I think he just wants to give us an overview of this unit.
Delete-Kevin Meglathery
What would be the vector form of momentum.
ReplyDeleteI don't know if there is an exact form of momentum as a vector. All I know is that it is one and therefore can be positive or negative.
Delete-Kevin Meglathery
i updated my java and everything, but it still says it is a blocked plug-in. it's just the newton's cradle simulator right? It is alright if i cannot see it?
ReplyDeleteWell, you don't need it to answer the questions but it would help.
ReplyDeleteAre we supposed to answer the questions and hand them in tomorrow or no?
ReplyDeleteFor 4th mod he didn't mention it, so I don't think so.
DeleteThese are just the objectives of this lesson. We haven't covered everything listed, so we wouldn't be able to fully answer the questions if they were due. I would assume that he posted these so we know what to expect and what we should be able to understand by the end of the unit.
DeleteI think we just have to know the answers to the questions. I don't think we have to write them down in our notebooks.
Delete-Skylar Young
Keep in mind everyone that he has done this before. He posted the things we should know, but didn't require us to write it down and show him.
Delete-Kevin Meglathery
For the hw, is everyone going to have the same numbers because when I opened the tab back up, the numbers were different from what I had seen earlier.
ReplyDeleteThey won't be the same. The wording for all of them is the same, but the numbers are changed each time. As long as we show the work, we should be good.
Delete-Kevin Meglathery
Which questions are we supposed to answer? The first five on the online test? The first five objective questions? Or something else entirely?
ReplyDelete-Kevin Meglathery
Oops...nevermind...apparently, "HW Problems 1-5" is a hyperlink.
Delete-Kevin Meglathery
Would recoil velocity be the same as the after velocity?
ReplyDeleteYes, as long as you are talking about the barrel/cannon/whatever is actually sending the projectile.
DeleteWhen are the 1-5 questions due? And are they graded?
ReplyDeleteTomorrow. Probably just for completion.
Delete-Kevin Meglathery
It doesn't matter if you have the right answer or not. What matters is whether or not you have the correct thought process, understanding and PUKE.
DeleteAnd my replies aren't working on my phone unless I use the blogger app.
ReplyDeleteI'm sorry for the inconvenience.
Delete-Kevin Meglathery
I'm just helping Mr. Crane out with fixing the blog. I appreciate your sympathy.
DeleteOne more thing. Number 3 on the test has the velocity of a car, but it's a blank rectangle. Anyone know what it is?
ReplyDelete5m/s.
Delete-Kevin Meglathery
That's why he posted the y = 5 m/s, as Kevin said.
DeleteSorry, I looked but I didn't see it posted.
DeleteI thought the y=5m/s is for the HW not the test! 5 m/s doesn't make sense on the test.
Delete-Robyn K
Everyone has different numbers for all the questions. How is y in every question 5m/s? its not possible. And you can't solve for y without having the mass of the bat.
ReplyDeleteIt is possible to solve the equation without the mass of the bat because we aren't looking for the momentum of the bat.
DeleteWe know the momentum of the ball before and after being hit.
We know the time that it is in contact with the bat.
We know the equation to find the impulse (it's in the coloring packet.)
From there, it's pretty easy. Granted, my answer seems entirely unrealistic, but I did get an answer.
-Kevin Meglathery
is this what we learned on friday ? i wasnt there....
ReplyDeleteIts just a bunch of different questions involving momentum and force and stuff we have learned in the past.
Delete-Catherine Samara
Basically, by using the one equation we learned on momentum and the fact that momentum is conserved, you'll be able to answer these questions. The main goal of these questions are to see that you can apply your knowledge to it through PUKES, so it's alright if your answer isn't right, as long as you had the right process.
DeleteThe entire layout of the blog has changed on my computer. I am using Google Chrome as suggested and everything is white and resembles the layout and interface of the mobile version. The "large white rectangle" was dark and had a puzzle piece. I was also notified that an updated JAVA was required to display some elements which has never happened before.
ReplyDeleteafter logging into google/blogger account the layout has been restored to the standard black background. If anybody had the problem with the white background, log in and see if that changes anything
DeleteSo we are going to have an online quiz for momentum like the Newton's Law ones? Or are the questions the quiz?
ReplyDeleteHe posted a Momentum Test earlier today, but something went wrong with it, which is why it says it'll be reposted ASAP. You'll have to wait for tomorrow at the earliest for it to be fixed, and it will be due by class on Friday.
DeleteI installed the Java update that it was asking me to and the Newton's Cradle program showed up. So the White Rectangle/Puzzle Piece was the Newton's Cradle program
ReplyDeleteIt supposedly was just a simulator. You can look up Newton's Cradle online and a bunch of interactive websites with a lot of information showed up!!
Delete-Catherine Samara
Mr. Crane, on the momentum test, question 3 doesn't have the velocity for the second cart and answers a and c on question 43 are the same and the answers b and d are also the same. I was wondering if you can give us this information. thank you
ReplyDelete-Matt Nazha
The test isn't working right now, and Mr. Crane is in the process of fixing it.
Delete-Kevin Meglathery
It still has the same answers. D:
Deleteit will work very soon it almost loaded for me today.
ReplyDeleteAnyone know what the three ***'s mean in 24?
ReplyDeleteI don't think they mean anything. The question still makes sense without them there, so I guess we just ignore it.
Delete-Kevin Meglathery
When is the test due?
ReplyDeleteThursday at 11:59 P.M.
Delete-Kevin Meglathery
For number 36, I got different answers when I used impulse = Ft verses impulse = m *(change in)velocity. Anyone else having this problem?
ReplyDelete-Robyn K.
IF we were to want to know the force at which something is traveling, we would have to know the speed and/or velocity, right?
ReplyDeleteWhat does "Force at which something is traveling" mean? (Doesn't make sense)
DeleteMomentum=mass*velocity
Force=mass*acceleration
i meant if we had to know the force (momentum), then we would need velocity right?
DeleteForce=/=momentum
DeleteTo calculate the momentum of an object you need the velocity and the mass. m*v=momentum
For the speed after a collision, is there a specific equation we should know? Or does the regular (momentum=mass X velocity) work?
ReplyDeleteThe equation is different depending on the situation, but since momentum is conserved, the total momentum before and after a collision will be equal. p (before)= p (after)
DeleteTo get the momentum of an object, you will still use m*v.
DeleteWith the Earth problem on the test, is there any way to solve that?
ReplyDeleteThat's number 30, right? If it is, then yes. Mr. Crane is always talking to us about the importance of maximums and minimums. This problem shows the concepts of momentum and Newton's 3rd Law in the absolute extreme maximum. Just go on Google to see which way the Earth spins and then think; if everything moved one way, what would the Earth do in response?
Delete-Kevin Meglathery
HELP! The link titled "HW Problems 1-5" is refusing to open. When I click it, it takes me to a new tab where I am informed that Chrome could not open the page. Is anybody having the same problem? Does anybody have a solution or the problems themselves?
ReplyDeleteLee has a mass of 42.8 kg and ice skates with a speed of 3.52 m/s. She collides into Mat (62.3 kg) who is standing still on the ice. They move off together. What is their final speed in m/s?
DeleteA 18.6-kg gun at rest contains a 0.0022-kg bullet. When fired, the bullet leaves the gun with a forward velocity of 179 m/s. What is the recoil velocity of the gun in m/s?
A 63 g ball moving to the right at 10.6 m/s is struck by a bat causing it to move to the left with a speed of [y] m/s. If the bat and ball are in contact for 0.01218 s, what is the average force in N exerted by the ball on the bat?
A 51-kg boy running at 8.81 m/s jumps onto a stationary cart. They move off together at 3.92 m/s. What is the mass of the cart in kg?
A 125 kg football player running 3.45 m/s in the positive direction tackles a 92.4 kg opponent running toward him at 10.0 m/s and holds on. What is their velocity in m/s just after the collision?
-Kevin Meglathery
Oh yeah, don't forget that for number three, y=5m/s.
Delete-Kevin Meglathery
This comment has been removed by the author.
ReplyDeleteThe home work questions 1-5 are due before class Thursday, and the online momentum quiz is due Thursday night.
DeleteHow would we be able to figure out 41? Both the ball and silly putty bounce. I'm assuming the silly putty isn't a ball for the question to work but you know what happens when you assume.
ReplyDelete-Will F
I was also having the same issue with that. Since they have the same mass, they would have to bounce an equal height.
ReplyDelete-Kyle Osterman
I'm pretty sure that silly putty doesn't bounce unless it's a ball. Considering that it doesn't say it's a ball, I guess we can say that we just have a randomly sized piece of sill putty.
Delete-Kevin Meglathery
Ok thanks Kevin. Will and i were talking on Skype for a while about this problem. That helped clear up our confusion!
Delete-Kyle Osterman
Yeah, it would probably be best to assume the putty doesn't bounce, considering that would complicate number 41, and Mr. Crane always tells us to go with the most simple explanations/solutions.
DeleteIn relation to question 33, here's a movie trailer
ReplyDeletehttp://www.youtube.com/watch?v=NlOF03DUoWc
-Will F
For number three on the homework, it is asking the average force in N exerted by the ball on the bat, what equation could i use to find that?
ReplyDeleteF=ma
Delete(Find the acceleration using acceleration=Change in Velocity/Change in time)
All of the problems in the homework were plug in chugs. As long as you drew pictures, kept in mind that momentum was conserved, and applied the correct equation, you should be fine.
DeleteFor those of you in my physics class (not sure if others did this), I wanted to see if anyone could figure out why the egg won't break against the sheet. I know why, but I wanted to see if anyone else could figure it out.
ReplyDelete-Will F
the faster you change the speed of an object, the greater the force applied to the object will be. by throwing an egg at a sheet, the sheet changes the speed of the egg slowly. it decreases the force applied to the egg when you throw it at the sheet and it will not break.
Deleteis there a specific equation for recoil velocity or should that be done the same way as #1 in the homework questions ??
ReplyDeleteBree, i think it might be the same equation. BEcause we are given the weight of both objects.
Deletescratch that, i think its a different equation. i think it might be Pb=P1a+P2a
DeleteFor that one, just remember that momentum is conserved. Because the gun and bullet start at rest, momentum is zero. So whatever the bullet's momentum is has to be equal and opposite to the gun's momentum. Find the momentum of the bullet, then use that to figure out the recoil velocity.
Delete-Kevin Meglathery
What did I miss in period 4 today?
ReplyDelete-Kevin Meglathery
We threw eggs at things.
Delete( To determine how a blanket extends the period of time of force used on an egg thrown at it to stop it. )
DeleteIs impulse equal to the change in the time multiplied by the force acting on it?
ReplyDeleteYes.
DeleteIt is also equal to the Change in Velocity*mass.
For number 30 on the quiz, does Earth spin clockwise or counterclockwise?
ReplyDelete-Rachel Krulish
Counterclockwise
DeleteDid anyone notice that 43. has the same answer twice?
ReplyDeleteHELP!
Well if he put the same answer twice, it could possibly suggest that that answer choice is wrong. In this case, I got the repeated answer as my solution, so I guess you would just have to choose one of them.
DeleteA and C are the same, as are B and D. My guess is that if you have one of the right answers, he'll give you credit.
Delete-Kevin Meglathery
Thanks. That was what I was thinking, but I just wanted to check. Also, I wanted to make sure I wasn't just crazy thinking A and C were the same answer.
DeleteCan someone give me some insight on what they put for #6? i know that if you increase the time or the force the momentum will increase, but i'm not sure if swinging as hard as you can is considered increasing the force.
ReplyDeleteBecause one of the choices is all of the above, if you find that two of the answers are possible, then it has to be all of the above. To answer your question though, swinging as hard as you can would be considered increasing the force because that would be the maximum force that could be applied.
Deleteyea, ok thx
DeleteIs the equation of impulse the same as the equation for momentum?
ReplyDeleteNo, I don't think so. Impulse is the time and momentum is how hard it is to stop it.
DeleteImpulse=force*time
Momentum=mass*velocity
While they are similar and related to each other, they aren't the same thing.
-Kevin Meglathery
They are slightly different from each other because impulse is the change in momentum.
DeleteCheck your cartoon guide to physics... They are close but still different... Example an object that has a constant velocity will have a change in momentum of 0.
ReplyDeleteDoes anyone know why 24 has stars?
ReplyDelete-Catherine Samara
Oh wait it was already answered my bad
Delete-Catherine
For 56, does he want us to convert to the SI Units, or leave it in km/h?
ReplyDeleteNever mind, I got it.
Deletei was thinking the same thing, i would assume leave in km/h but im not sure
DeleteYeah, that's what I ended up doing.
Deletemy computer wont let me on the test... anyone else having trouble?
ReplyDeleteI didn't have any trouble taking it. Maybe try using a different browser?
Deletei had the same problem so i tried using chrome and it worked
DeleteMr. Crane said Google Chrome is the optimal browser for all your blog-related needs, and it is.
DeleteAre force and impulse the same thing? Impulse is m(delta v)/(delta t) and change in velocity over change in time is acceleration. That means that impulse is mass times acceleration, which is also force. A net force will cause an acceleration which changes the velocity, and if the velocity changes, so will the impulse because velocity is a part of momentum and impulse is a change in momentum. Is this true?
ReplyDeleteImpulse and force are related, but they are not the same thing. I think you have the definition of impulse mixed up with something else, because impulse is the change in momentum, which is Force x Change in Time. That would be how much force occurs in a certain amount of time. You are right about the changing velocity though, since a force, pushing for t seconds will produce a change in velocity of whatever it is pushing on. Because you need force to find the impulse, they are separate but related concepts.
DeleteImpulse =/= m(delta v)/(delta t)
DeleteImpulse is equal to m*delta v or Force*delta t.
I believe the advertisement for Silly Putty claims that is has bouncing qualities
ReplyDeleteFor #27, are the gliders moving in opposite directions or in the same
ReplyDelete~Taylor Nardone