If an object with a mass of #15 kg # changes speed from #25m/s# to #14 m/s#, by how much does its kinetic energy change? Physics Work and Energy Energy 1 Answer ali ergin Feb 13, 2016 #Delta E_k=-3217,5J# Explanation: #Delta E_k=1/2*m(v_f^2-v_i^2)# #Delta E_k=1/2*15(14^2-25^2)# #Delta E_k=1/2*15(196-625)# #Delta E_k=-1/2*15*429# #Delta E_k=-3217,5J# 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 1313 views around the world You can reuse this answer Creative Commons License