Question

Calculate the kinetic energy of a 45 gram golf ball traveling at 20 m/s

Answer 1

Kinetic energy = (1/2) (mass) x (speed)² .

KE = (1/2) (0.045 kg) x (20 m/s)²

KE = (0.0225 kg) x (400 m²/s²)

KE = (0.0225 x 400) (kg-m²/s²)

KE = 9 (kg-m/s²) (m)

KE = 9 Joules

Answer 2

The kinetic energy of a 45 gram golf ball traveling at 20 m/s is 9 Joules .

Step-by-step explanation:

Given:

Mass of the golf ball= 45 gram

velocity at which the golf ball travels=20m/s

To Find:

Kinetic energy=?

Solution:

We define kinetic energy as the energy gained by a body by virtue of its motion or from its state of rest to its motion.It’s unit is Joules.

`\text{kinetic energy} = (1)/(2) mass* velocity^2`

Mass= 45 grams

Converting into kg

1000 grams = 1 kilogram.

45grams= 0.045kg

Also velocity given as 20 m/s

Hence substituting the values

Kinetic Energy=
`(1)/(2) *0.045* (20)^2`

Kinetic Energy=9 Joules .