A trolley of mass 20kg is initially moving due east with a velocity of 2ms−1. After a brief push, its momentum becomes 60kgms−1 towards the west.
a. (i) Calculate the initial momentum of the trolley, stating its direction.
b. (ii) Determine the change in momentum of the trolley. Express its magnitude and direction.
c. (iii) Explain what the direction of the change in momentum tells you about the direction of the net force applied during the push.
d. (iv) Distinguish between mass and momentum with reference to the values used in this example.