Two equal-magnitude forces are applied to a door at the doorknob. The first force is applied perpendicular to the door, and the second force is applied at 60Â° to the plane of the door. Which force exerts the greater torque about the door hinge?

A. the first force (applied perpendicular to the door)

B. Both forces exert equal non-zero torques

C. Both forces exert zero torque

D. the second force

Question

Physics

Andre Miller

11 February, 23:03

Two equal-magnitude forces are applied to a door at the doorknob. The first force is applied perpendicular to the door, and the second force is applied at 60Â° to the plane of the door. Which force exerts the greater torque about the door hinge?

A. the first force (applied perpendicular to the door)

B. Both forces exert equal non-zero torques

C. Both forces exert zero torque

D. the second force

+4

Answers (1)

Know the Answer?

Ewing · Answer 1

option (A)

Explanation:

Torque is defined as the

Torque = Force x distance x SinФ

Where, Ф is the angle between force vector and the displacement

In case I:

torque = F x r x Sin 90 = F x r

In case II:

Torque = F x r x Sin 60 = 0.866 F r

So, the torque is more in first case.

Thus, option (a) is correct.