Super elastic collision between two objects

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The discussion revolves around a physics problem involving a super elastic collision between two masses, m1 and m2, with specific parameters provided. The user initially struggles with calculations related to momentum and kinetic energy conservation, particularly in determining the velocity required for mass m2 to reach a designated point. Key insights include applying the conservation of energy to find the necessary speed for m2 and understanding how the spring's force affects m1's velocity. Ultimately, the user successfully calculates the compression distance of the spring, concluding with a value of 5.8 cm. This highlights the importance of energy conservation and kinematic principles in solving collision problems.
noffya
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Hello,
I have difficulties with this problem:

The body mass m1 = 20 g is fired with a spring, k = 72 N / m from position A. On arrival at point B hits completely elastic body mass m2 = 15 g.

Find the distance x of compressed spring so that the mass m2 reaches point C separated a distance d = 90 cm from point O. Data: h = 25 cm.

I was trying to do the calculations and camera up with these:
Since momentum P and cinetic energy are constant therefore m1*v0=m1v1+m2v2 and 1/2m1v0=1/2m1v1 +1/2m2v2
To find the v2 of the object m2 I apply conservation of energy law and it sums up to 1/2m2v2 = m2gh

After making calculations I get stuck and I think I'm missing something.
Please give an advice with this.
Thanks
 

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Ask yourself: How fast must m2 have been going to land at point C?
 
Here are some useful things which I will leave for you to find (if you get stuck, ill show you how).

1. How fast does m2 have to go? (Kinematics)
2. If m2 has to go "v" meters per second, how fast would m_1 need to go right before they collide?
3. F=-kx, and F=ma, so the spring provides an acceleration to m_1 when released. How does this affect m1's speed
 
oneplusone said:
Here are some useful things which I will leave for you to find (if you get stuck, ill show you how).

1. How fast does m2 have to go? (Kinematics)
2. If m2 has to go "v" meters per second, how fast would m_1 need to go right before they collide?
3. F=-kx, and F=ma, so the spring provides an acceleration to m_1 when released. How does this affect m1's speed

Doc Al said:
Ask yourself: How fast must m2 have been going to land at point C?
Thanks for hints!
 
oneplusone said:
Here are some useful things which I will leave for you to find (if you get stuck, ill show you how).

1. How fast does m2 have to go? (Kinematics)
2. If m2 has to go "v" meters per second, how fast would m_1 need to go right before they collide?
3. F=-kx, and F=ma, so the spring provides an acceleration to m_1 when released. How does this affect m1's speed

Got it. I applied energy conservation law at step 3 and got the x equals 5.8cm
Thanks a lot!
 
The book claims the answer is that all the magnitudes are the same because "the gravitational force on the penguin is the same". I'm having trouble understanding this. I thought the buoyant force was equal to the weight of the fluid displaced. Weight depends on mass which depends on density. Therefore, due to the differing densities the buoyant force will be different in each case? Is this incorrect?

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