If an object with a mass of # 3kg # changes speed from #5m/s# to # 1m/s#, by how much does its kinetic energy change?

1 Answer
Apr 4, 2016

Answer:

#Delta E_k=-36 J#

Explanation:

#v_f=1 m/s#
#v_i=5 m/s#
#m=3 kg#

#Delta E_k=1/2*m(v_f^2-v_i^2)#

#Delta E_k=1/2*3*(1^2-5^2)#

#Delta E_k=3/2(1-25)#

#Delta E_k=-3/cancel(2)*cancel(24)^12#

#Delta E_k=-3*12#

#Delta E_k=-36 J#