If an object with a mass of #2 kg # changes speed from #3 m/s# to # m/s#, by how much does its kinetic energy change?
1 Answer
May 14, 2016
Explanation:
Recall that the formula for kinetic energy is:
#color(blue)(|bar(ul(color(white)(a/a)DeltaE_k=1/2mv^2color(white)(a/a)|)))# where:
#DeltaE_k=# change in kinetic energy
#m=# mass (kilograms)
#v=# velocity (metres per second)
Start by breaking down
#DeltaE_k=1/2mv_f^2-1/2mv_i^2#
Simplify.
#DeltaE_k=1/2m(v_f-v_i)^2#
Substitute the given values.
#DeltaE_k=1/2(2kg)(1m/s-3m/s)^2#
Solve.
#DeltaE_k=1/2(2kg)(4m^2/s^2)#
#DeltaE_k=color(green)(|bar(ul(color(white)(a/a)color(black)(4J)color(white)(a/a)|)))#