Question

A stone has initial potential and kinetic energy as 5 J and 20 J respectively if the final kinetic energy of the stone is 15 J what is its final potential energy?

(a) 0

(b) 10 J

(c) 15 J

(d) 25 J

I had been asked this question in homework.

This question is from Internal Energy and Energy Conversion Concept in division Introduction to Energy Balances for Processes without Reaction and Calculation of Enthalpy Changes of Basic Chemical Engineering

Answer 1

Correct answer is (b) 10 J

To elaborate: 5 + 20 = 15 + PE, => PE = 10 J.