Answer: 9
Explanation:
Kinetic energy is the energy possessed by a moving object. It is measured in joules, and depends on the mass (m) of the object and the speed (v) by which it moves i.e K.E = 1/2 x mass x velocity^2
So, car is traveling 120 km/h
KE = 1/2x m x (120 km/h)^2
KE = 0.5 x m x 14400
KE1 = 7200m
So, car is traveling 40 km/h
KE = 1/2x m x (40 km/h)^2
KE = 0.5 x m x 1600
KE2 = 800m
Now, divide the value of kinetic energy obtained during 120 km/h by that obtained during 40 km/h
i.e 7200m / 800m
= 9
Thus, the kinetic energy will be 9 times more at a speed of 120 km/h than at 40 km/h
