Bart carried his skateboard up a hill and then rode the skateboard down the hill. When he reached the bottom of the hill, he rolled to a stop. When did Bart have the most potential energy?

Explanation:

The potential energy of an object is given by :

P = mgh

Where,

m is mass, g acceleration due to gravity and h is the height reached by the object.

The potential energy of an object is directly proportional to the height of the object. It means that when the skateboard reaches at the maximum height, it has highest potential energy.

initial speed when it is dropped is 150 ft/s

now at the same moment the acceleration due to gravity is perpendicular to its velocity

so as we know that

now we have centripetal acceleration a = 32 ft/s^2 as its perpendicular to velocity

while tangential acceleration at the same moment will be zero

so

now radius of curvature is given as

so the radius of curvature just after it is dropped is 703.125 ft