The Kinetic Energy Formula is as follows: KE = mass x velocity^2 / 2
Plug in the correct numbers into the units!
KE = 4 kg x 16 m/s ^2 / 2
Square the 16 m/s.
KE = 4 kg x 256 m/s / 2
Multiply 4 x 256
KE = 1,024 / 2
Divide!
KE = 512 Newton-meters or Joules!!