If an object with a mass of #2 kg # changes speed from #9 m/s# to #12 m/s#, by how much does its kinetic energy change?

1 Answer
Jun 14, 2018

Answer:

The change in kinetic energy is #=63J#

Explanation:

The kinetic enegy is

#KE=1/2mv^2#

The change in kinetic energy is

#DeltaKE=1/2mv^2-1/2mu^2=1/2m(v^2-u^2)#

The mass is #m=2kg#

The initial speed is #u=9ms^-1#

The final speed is #v=12ms^-1#

The cgange in kinetic energy is

#DeltaKE=1/2*2*(12^2-9^2)=63J#