Potential and Kinetic Energy - Math Problems

Question

1. A 50 kg diver stands motionless at the top of 10.0 meter high dive. What is her potential energy?
2. Your pet puppy Scruffy can run up to 2 meters/sec (m/s) on his fastest days. Scruffy has a mass of 8 kg. What is his maximum kinetic energy on his fastest days?

Answer 1

P.E. = m x g x h

P.E. = potential energy = ?

m = mass = 50 kg

g = gravity = 9.81 m/s²

h = height = 10.0 m

P.E. = (50 kg)(9.81 m/s²)(10.0 m) = 4905 Joules (kgm²/sec²)

K.E. = 1/2 mv²

K.E. = kinetic energy = ?

m = mass = 8 kg

v = velocity = 2 m/s

K.E. = 1/2 (8 kg)(2 m/s)² = 16 kgm²/s² = 16 Joules