If an object with a mass of #5 kg # changes speed from #5m/s# to # 7m/s#, by how much does its kinetic energy change?

1 Answer
Apr 3, 2016

Answer:

Equation: #E_(k)=1/2*m*v^2#

Explanation:

At #5m//s#: #E_k=1/2*5*5^2=62.5J#

At #7m//s#: #E_k=1/2*5*7^2=122.5J#

Difference: #122.5-62.5=60J#

Check your answer :
Kinetic energy changes as the square of the velocities:
#(7/5)^2=1.96#, allmost double. Check!