Question

The ball has 7.35 joules of potential energy at position B. At position A, all of the energy changes to kinetic energy. The velocity of the ball at position A is meters/second. Assume there’s no air resistance. Use g = 9.8 m/s2 , PE = m × g × h, and . mass is 1.5 kilograms and g= 9.8 and the hight of position b is 0.5 meters.

Answer 1

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:

`K= (1)/(2)mv^2`
And since K=7.35 J, we can find the velocity, v:

`v= \sqrt{ (2K)/(m) }= \sqrt{ (2 \cdot 7.35 J)/(1.5 kg) }=3.1 m/s`