# If an object with a mass of 12 kg  changes speed from 1 m/s to 2 m/s, by how much does its kinetic energy change?

Dec 10, 2015

The kinetic energy increases by $6 \text{J}$

#### Explanation:

The expression for kinetic energy is :

$K E = \frac{1}{2} m {v}^{2}$

The initial $K E$ is :

$\frac{1}{2} \times 12 \times 1 = 6 \text{J}$

After the increase in speed this becomes:

$\frac{1}{2} \times 12 \times 2 = 12 \text{J}$

So you can see that the $K E$ has increased from 6 to 12J which is an increase in 6J.