Question

What is the kinetic energy of a 2,000 kg boat moving at 5 m/sec?

Answer 1

Kinetic energy = mv^2/2 = 2000x5^2 /2 = 25000J or 25KJ.

Answer 2

         Kinetic energy  =  (1/2) x (mass) x (speed)²

                                   = (1/2) x (2000 kg) x (5 m/s)²

                                   =  (1,000 kg)  x  (25 m²/s²)

                                   =        25,000 kg-m²/s²

                                   =        25,000 joules