3. a ball is thrown straight up with an initial velocity of 40 m/s.
a. what is its velocity at the top of its path?

The velocity at the top of its path will be zero (0)

Explanation:

We can solve this problem or particular situation using the principle of energy conservation.

Which tells us that energy is transformed from kinetic energy to potential energy and vice versa. A reference point should be considered at which the potential energy is zero, and at this point the initial velocity of 40 [m/s] is printed to the ball.

The potential energy is determined by:

The kinetic energy is determined by:

This will be the maximum path but, its velocity at this point will be zero. Because now all the kinetic energy has been transformed in potential energy.

it may be wrong but i think its a

a coal burning power plant