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Problem:

A 50 kg boy runs at a speed of 10 m/s and jumps onto a cart. The cart is initially at rest. If the speed of the cart with the boy on it is 2.50 m/s, what is the mass of the cart?

I don't know what to do. This probelem seems very simple but I don't know where to start.

These I know are the knowns:

vo(cart) = 0 m/s

vf(cart) = 2.50 m/s

vo(boy) = 10 m/s

vf(boy) = 2.5 m/s

So I know velocities and I know the mass of the boy.

Should I start off by finding the acceleration from F=ma, since I know a mass? But then I don't know how to find F. I know Fn = mg in the y component, but I don't know what I would use Fn next for. Am I supposed to use kinematics equations? But I don't know a, x, or time. Direction is needed, thanks!!

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# Homework Help: What is the mass of the cart?

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