If an object with a mass of # 3kg # changes speed from #5m/s# to # 6m/s#, by how much does its kinetic energy change?

1 Answer
Apr 18, 2018

Answer:

#"16.5 J"#

Explanation:

Kinetic energy is given by

#"K" = 1/2\ "mv"^2#

#"K"_1 = 1/2\ "mv"_1^2#

#"K"_2 = 1/2\ "mv"_2^2#

Subtract first equation from second

#"K"_2 - "K"_1 = 1/2\ "mv"_2^2 - 1/2\ "mv"_1^2#

#color(blue)(Delta"K" = 1/2\ "m"["v"_2^2 - "v"_1^2])#

Plug in the values

#Δ"K" = 1/2 × "3 kg" × [("6 m/s")^2 - ("5 m/s")^2] = color(green)"16.5 J"#