Ricocheting Bullet (elastic collisions)

AI Thread Summary
A 0.100-kg stone on a frictionless surface is struck by a 6.00g bullet traveling at 350 m/s, which rebounds at a right angle with a speed of 250 m/s. The key confusion arises from visualizing the bullet's trajectory and its rebound direction, as it initially travels horizontally but then bounces off at a right angle. The discussion emphasizes the importance of conserving momentum in both the North-South and East-West directions during the collision. Clarifying the coordinate system helps in understanding the problem, with the bullet's initial and final velocities needing to be defined correctly. Overall, the momentum conservation principle is crucial for solving the problem accurately.
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Homework Statement


.100-kg stone rets on a frictionless, horizontal surface. A bullet of mass 6.00g, traveling horizontally at 350 m/s, strikes the stone and rebounds horizontally at right angles to its original direction with a speed of 250 m/s. (a) Compute the magnitude and direction of the velocity of the stone after it is struck.


Homework Equations


Kfinal=Kinitial
Pfinal=Pinitial


The Attempt at a Solution


My problem with this question is that I cannot visualize it so I do not know how to try and solve it. I am confused because the bullet is initially traveling horizontally, but then is rebounding horizontally but at a right angle to the horizontal...? I thought it was just giving me the x-component of velocity for the bullet, but wouldn't the situation described be vertical?
 
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It bounces off horizontally,
Picture it coming in from the north, hitting a 45degree angle face of the stone and bouncing off going east.

The important point is that the total momentum in each direction (eg North-South and East-West) must be the same before and after.
 
If it is coming from the north, wouldn't it be coming in with a vertical velocity? Or is this just a matter of defining axes?
 
North as on a map.
Or if you prefer imagine a flat piece of graph paper where the bullet is coming down the y-axis and bounces off up the x-axis.
 
Last edited:
ohhhhhh. that makes sense.
thank you so much for your quick reply!
 

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