# 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?

##### 1 Answer

Apr 5, 2018

#### Answer:

#### Explanation:

Kinetic energy is given as

#"KE" = 1/2\ "mv"^2#

Initial kinetic energy

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

Final kinetic energy

#"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!