A science club compares the motion of four trolleys A, B, C and D moving on a smooth horizontal track. Their masses and speeds are expressed in terms of two positive quantities m and v as shown below:
Trolley Mass Speed
A 2mv
B m2v
C 4m21v
D 21m3v
Without performing full numerical calculations, use reasoning to decide which trolley possesses the greatest and which possesses the least kinetic energy. Give a proper justification for your answer by referring to the data in the table.
a. (i) Explain qualitatively how the kinetic energy of an object depends on its mass and on its speed.
b. (ii) Using your explanation in part (i) and the data given, arrange the four trolleys in ascending order of their kinetic energies. State clearly which factors guided each step of your reasoning.