## Block move down the curved hill and hit attached block spring with diagram

A 100grams block is moving at 2m/s down the curved hill. The block slides along the smooth surface and collides elastically with the 400gram block. The 400gram block is initially at rest and is attached to an ideal spring with spring constant of 500N/m
a)Find the maximum distance the spring compresses
b)Find the maximum height the 100gram block reaches after the collision.

I added a diagram....... help me T.T
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 oh~ height is 3.0m.......

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Hi cecico! Welcome to PF!
 Quote by cecico A 100grams block is moving at 2m/s down the curved hill …
I don't understand … it will be accelerating … at which point is its speed 2m/s?

## Block move down the curved hill and hit attached block spring with diagram

Someone else asked this exact same question on another thread, and that poster made the same mistake you did-- you have not attempted the problem. You must show that you have worked on the problem before asking for help.

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 Quote by DavidWhitbeck Someone else asked this exact same question on another thread, and that poster made the same mistake you did-- you have not attempted the problem. You must show that you have worked on the problem before asking for help.
Not someone else.

 Quote by Saladsamurai In order to receive help with this problem I suggest that you a) Provide a diagram b) Show the work you have tried thus far. Forum rules.
To start you off. I would ask my self what theory(s) I would like to apply to solve this problem. What theories have you learned that involve finding velocities and displacements?

Work-Energy theorem and Conservation of Energy come to mind. Which would be easier in this case?

 Quote by tiny-tim Hi cecico! Welcome to PF! I don't understand … it will be accelerating … at which point is its speed 2m/s?
And this too. Where is its velocity 2 m/s ?

 Oh you're right SaladSamurai! That poster must be impatient.
 SaladSamurai your right........ I have to use Work-Energy theorem and Conservation of Energy and the speed is 2m/s at point A and the surface is smooth.......

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 Quote by cecico … the speed is 2m/s at point A …
Hi cecico!

ok … then what is the speed of the 100grams block just before it hits the other block?

 according to my calculation I got 7.925m/s.........after this i have no idea.....

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 Quote by cecico according to my calculation I got 7.925m/s.........after this i have no idea.....
That's right.

Now pretend that there's no spring, and work out the speeds of the two blocks immediately after the collision.

 immediately after the collision I got 1.585m/s.... is this right??????????

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 Quote by cecico immediately after the collision I got 1.585m/s.... is this right??????????
uuh? you should get two speeds … one for each block!

(and if you show your working, that'll save me time checking! )

 ok......now i really don't get it..... what equation do i have use?? momentum equation???? Mv+Mv=Mv+Mv but theres two unknown..... how do i calculate this????????? -0-

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 Quote by cecico ok......now i really don't get it..... what equation do i have use?? momentum equation???? Mv+Mv=Mv+Mv but theres two unknown..... how do i calculate this????????? -0-
Hi cecico!
DON'T PANIC!

(i can tell you're panicking because the number of question marks is increasing faster than exponentially!!)

In collisions, momentum is always conserved.

And you're told that this collision is elastic, and that means that energy is also conserved.

Two equations … two unknowns … physicist's heaven!

 alright for 100gram I got -4.755m/s and for 400gram I got 3.17m/s......it seems wrong..T.T
 Blog Entries: 27 Recognitions: Gold Member Homework Help Science Advisor Well, let's assume it's right. You now have an initial velocity for the 400gram block. So … what is the maximum distance the spring compresses?
 I got 0.08966m........