If an object with a mass of # 3kg # changes speed from #5m/s# to # 1m/s#, by how much does its kinetic energy change? Physics Work and Energy Energy 1 Answer ali ergin · A08 Apr 4, 2016 #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# Answer link Related questions How do matter and energy interact? Question #50ca2 Question #242cf Question #5038d Question #50391 What is potential energy? Question #d6576 Question #50cae Question #50cb2 Question #50cb6 See all questions in Energy Impact of this question 1562 views around the world You can reuse this answer Creative Commons License