It would be helpful if you gave me a bit more information on what the cars speed is
D.
Always use the right tool to get accurate measurements
I assume that the ball is stationary (v=0) at point B, so its total energy is just potential energy, and it is equal to 7.35 J.
At point A, all this energy has converted into kinetic energy, which is:

And since K=7.35 J, we can find the velocity, v:
Sicko
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