Question

A 3kg book is resting high on a book shelf. If the book has 73.5 J of potential energy, how high is the shelf?

2.5m

If this book slipped off the shelf and fell all the way to the ground, how much kinetic energy would it have the instant it hit the ground (if we ignore air resistance)?

____J

Answer 1

0 J

Step-by-step explanation:

1. We know that U = mgh,
h = U/mg
or h = 73.5/3*9.8 = 2.5 m

2. When the book falls on the ground, there will be no kinetic energy by the book as the book will once again be stationary, and will convert this kinetic energy to other forms, so your answer must be 0 J.