What is the kinetic energy of an object with a mass of #3 kg# that has been in freefall for #7 s#? Physics Work and Energy Energy 1 Answer ali ergin May 19, 2016 #E_k=7073.35" "J# Explanation: #"first; let's find velocity of object for t=7"# #v=-g*t# #v=-9*81*7# #v=-68.67 m/s# #"The Kinetic Energy of an object is calculated by:" E_k=1/2*m*v^2# #m=3 kg# #E_k=1/2*3*(-68.67)^2# #E_k=7073.35" "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 1334 views around the world You can reuse this answer Creative Commons License