Question

Find τn, the torque about point P due to the normal force.

a) τn = 0
b) τn = Fr
c) τn = Fcos(θ)
d) τn = rF

Answer 1

The torque (τn) due to the normal force about a point P is given by the equation τn = rF, as the normal force acts perpendicular to the surface resulting in a 90-degree angle with the lever arm.

Step-by-step explanation:

The question asks to find the torque (τn) about a point P due to the normal force. Torque is defined as T = rF sin θ, where T is the torque, r is the distance from the pivot point to the point where the force is applied, F is the magnitude of the force, and θ is the angle between the force and the pivot point. The normal force always acts perpendicular to the surface, so the angle between the normal force and the lever arm is 90° (or π/2 radians), which makes sin(θ) equal to 1. Therefore, the torque due to the normal force can be expressed as τn = rF.