Lift examples part a, b & c: Charissa, Kaining, Fangci, Joe

For a & b, ignore the free body diagram for at the start since the scenario starts from when it is already moving.

For every part, take upwards as positive, m=20.0kg, acceleration due to gravity = -10ms^-2, F refers to the weight of the person and the dot in the free body diagram represents the whole lift. For both FBDs of parts a & b, F1 refers to the force exerted by the cable, and F2 represents the weight of the whole lift including the person and the weighing scale.

We have not done part d yet.

part a:

part b:

part c: