Question

A small dog is trained to jump straight up a distance of 1.2m. How much kinetic energy does the 7.2kg dog need to jump this high? (The acceleration due to gravity is 9.8m/s2.) Please show work & and explain in simple terms...

Answer 1

Remember that since energy is conserved, the kinetic energy it takes to jump to a height of 1.2 m is just the same as the potential energy difference between ground level and the 1.2 m height.
Potential energy = (mass)(gravity)(height) = (7.2 kg)(9.81 m/s^2)(1.2 m) = 84.76 J
Therefore, the kinetic energy required for the dog to jump to a 1.2-m height is 84.76 Joules.

Answer 2

The answer is A. 85 J
This is because we rounded 84.7 to 85