A penny falls off a building at 10m/s. The penny weighs 0.2kg. What is the energy?

Question

For me these kind of questions are hard for me. and it does not make sense at alll. i have low grade in physics class

Answer 1

When you are asked this type of question (a mass moving at a certain velocity), you have to think of kinetic energy which is a pretty simple equation,

KE = 1/2 x mass x velocity² = 1/2 x 0.2 kg x (10 m/s)² = 10 kg-m²/s² (joules)

1 joule = 1 newton x 1 meter = (1kg x 1m/s² ) x 1m