A stone of mass 500g is thrown vertically upwards with a velocity of 1

1.	A stone of mass 500g is thrown vertically upwards with a velocity of 15 m s-1. Calculate: (a) the potential energy at the greatest height, (b) the kinetic energy on reaching the ground, (c) the total energy at its half-way point.
Answer» (a) Potential energy at the greatest height = initial kinetic energy or, mgh = 1/2 mv² = 1/2 ×0.500 ×15 ×15=56.25J (b) Kinetic energy on reaching the ground= potential energy at the greatest height = 56.25 J (c) Total energy at its half-way point = 1/2 (K + U) = 56.25J.

A stone of mass 500g is thrown vertically upwards with a velocity of 15 m s-1. Calculate: (a) the potential energy at the greatest height, (b) the kinetic energy on reaching the ground, (c) the total energy at its half-way point.

Answer»

(a) Potential energy at the greatest height = initial kinetic energy

or, mgh = 1/2 mv²

= 1/2 ×0.500 ×15 ×15=56.25J

(b) Kinetic energy on reaching the ground= potential energy at the greatest height = 56.25 J