# If an object with a mass of 12 kg  changes speed from 9 m/s to 10 m/s, by how much does its kinetic energy change?

Apr 5, 2018

$\text{114 Joules}$

#### Explanation:

Kinetic energy is given as

${\text{KE" = 1/2\ "mv}}^{2}$

Initial kinetic energy

$\text{KE"_i = 1/2\ "mv"^2 = 1/2 × "12 kg" × ("9 m/s")^2 = "486 J}$

Final kinetic energy

$\text{KE"_f = 1/2\ "mv"^2 = 1/2 × "12 kg" × ("10 m/s")^2 = "600 J}$

Change in kinetic energy

Δ"KE" = "KE"_f - "KE"_i

Δ"KE = 600 J - 486 J" = color(indigo)("114 J"

I hope that helps!