If an object with a mass of #7 kg # changes speed from #3 m/s# to #8m/s#, by how much did its kinetic energy change by?

1 Answer
Jan 10, 2016

Answer:

I found: #DeltaK=192.5J#

Explanation:

You know that kinetic energy is given as:
#K=1/2mv^2#

So the change in kinetic energy will be:

#DeltaK=1/2mv_f^2-1/2mv_i^2=#

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

#=1/2*7*(8^2-3^2)=7/2(64-9)=192.5J#