Which has the least kinetic energy?

Question

Quizplus · Accepted Answer

Kinetic energy is directly proportional to the mass of an object and the square of its velocity. Therefore, we need to calculate the kinetic energy of each object to determine which one has the least amount. 
For option A, the kinetic energy is (1/2) * 1200 kg * (25 m/s)^2 = 937.5 kJ.
For option B, the kinetic energy is (1/2) * 1400 kg * (23.61 m/s)^2 = 982.35 kJ.
For option C, the kinetic energy is (1/2) * 1600 kg * (22.22 m/s)^2 = 1064.44 kJ.
For option D, the kinetic energy is (1/2) * 1800 kg * (20.83 m/s)^2 = 1125 kJ.
Therefore, option A has the least kinetic energy.

Which Has the Least Kinetic Energy