Answer the following questions related to the concepts of true weight and apparent weight:
a. (i) Define the terms true weight and apparent weight of a body.
b. (ii) Explain why a passenger inside a lift feels lighter when the lift accelerates downward but heavier when it accelerates upward.
c. (iii) Describe the condition under which the apparent weight of a body becomes zero and give a physical example of such a situation.
d. (iv) State one everyday situation (other than a lift) in which a human experiences a change in apparent weight and briefly explain the cause.