Question

A ball is projected vertically upwards and then returns to the ground. Ignore all frictional forces. Which one of the following statements about the kinetic energy and potential energy of the ball is true?

A)The kinetic energy is always equal to the potential energy
B)The kinetic energy is always less than the potential energy
C)The kinetic energy is always more than the potential energy
D)The sum of the kinetic energy and potential energy is always constant

Answer 1

Answer:

Explanation: option d

We know that the sum of kinetic and potential energy is always same in vertical motion at any point....

Answer 2

the answer to this question is (d)ie: sum of K.E +P.E is constant

at the topmost point K.E is zero and at the lower most point the P.E is zero

as there is no frictional forces the mechanical energy remains constant .

mechanical energy =P.E+K.E

hence sum of potential energy and sum of kinetic energy remains constant.