Question

4. A disobedient student dropped his Physics textbook (mass 0.1kg) from the window (15m above the ground). How fast was it going when it hit the ground?

Answer 1

Answer:

v= 17.15 m/s

Explanation:

mass of the book=0.1 Kg

height above ground, h= 15 m

Using conservation of energy

Potential energy is converted into kinetic energy

$mgh = \frac{1}{2}mv^2$

$v=\sqrt{2gh}$

$v=\sqrt{2\times 9.8\times 15}$

$v=\sqrt{294}$

v= 17.15 m/s

Hence, the book will hit the ground at the speed of 17.15 m/s.