Equilibrium: A woman is straining to lift a large crate, without success because it is too heavy. We denote the forces on the crate as follows: P is the upward force the woman exerts on the crate, C is the vertical contact force exerted on the crate by the floor, and W is the weight of the crate. How are the magnitudes of these forces related while the woman is trying unsuccessfully to lift the crate? A) P + C = W B) P + C W D) P = C

Question

Equilibrium: A woman is straining to lift a large crate, without success because it is too heavy. We denote the forces on the crate as follows: P is the upward force the woman exerts on the crate, C is the vertical contact force exerted on the crate by the floor, and W is the weight of the crate. How are the magnitudes of these forces related while the woman is trying unsuccessfully to lift the crate?
A) P + C = W
B) P + C < W
C) P + C > W
D) P = C

Quizplus · Accepted Answer

When the woman is trying unsuccessfully to lift the crate, it means the crate is not moving, so it is in equilibrium. Therefore, the sum of the upward forces (P + C) must equal the downward force (W) to satisfy the condition for equilibrium.

Equilibrium: a Woman Is Straining to Lift a Large Crate