Explanation:
Draw free body diagrams for the worker and the load.
The worker has three forces on him: normal force pushing up, weight pulling down, and tension pulling down.
The load has three forces on it: weight pulling down and two tension forces pulling up.
Sum of the forces on the load:
∑F = ma
2T - 480 N = 0
T = 240 N
Sum of the forces on the worker:
∑F = ma
N - 720 N - 240 N = 0
N = 960 N
So the pressure produced by the worker is:
P = F / A
P = 960 N / 320 cm²
P = 3 N/cm²
P = 30,000 Pa
