Chapter 8, Problem 2STP

To determine

To choose: The correct option.

Answer to Problem 2STP

The correct option is (A).

Explanation of Solution

Given:

The force exerted on the lever is $F=60\text{N}$ .

The length of the lever is $l=1.0\text{m}$ .

The angle between the force and the perpendicular to the lever is $\theta =30°$ .

Formula used:

The torque is the product of the lever arm and the applied force.

Consider a force $F$ is applied at the end of the lever at an angle $\theta$ with the perpendicular to the lever.

The expression for the torque is,

  $\tau =Fl\sin \theta$

Calculation:

The forces acting on the lever as shown in the figure below.

  

The torque applied on the lever is,

  $\begin{array}{l}\tau =Fl\sin \theta \\ \tau =\text{60}\text{N}\times \left(1\text{m}\right)\sin \left(30°\right)\\ \tau =3\text{0}\text{N}\cdot \text{m}\end{array}$

Conclusion:

Therefore, the torque applied on the lever is represented by option (A).