# If an object with a mass of  3kg  changes speed from 5m/s to  3m/s, by how much does its kinetic energy change?

Feb 9, 2016

$\Delta {E}_{k} = - 24 J$
$\Delta {E}_{k} = \frac{1}{2} \cdot m \left({v}_{l}^{2} - {v}_{i}^{2}\right)$
$\Delta {E}_{k} = \frac{1}{2} \cdot 3 \left({3}^{2} - {5}^{2}\right)$
$\Delta {E}_{k} = \frac{1}{2} \cdot 3 \left(9 - 25\right)$
$\Delta {E}_{k} = \frac{1}{2} \cdot 3 \left(- 16\right)$
$\Delta {E}_{k} = - 24 J$