Question

A body of mass \( M \) is moving with a uniform speed \( v \) on a frictionless horizontal surface under the influence of two forces \( F_1 \) and \( F_2 \) as shown in the figure. The net power of the system is:

• A. \( (F_1 - F_2)v \)
• B. \( 0.5 (F_1 + F_2)v \)
• C. \( (F_1 + F_2)v \)
• D. Zero

Hint:

For objects moving with uniform velocity under opposing forces, the net power is calculated as: \[ P = (F_{\text{net}}) v \] where \( F_{\text{net}} = F_1 - F_2 \).

Answer 1

The Correct Option is A

Step 1: Understanding Power in Motion The instantaneous power \( P \) is given by: \[ P = F \cdot v \] Since the body moves at a uniform speed, the net force acting on it is responsible for the power generation. Step 2: Net Force on the Body The forces \( F_1 \) and \( F_2 \) act in opposite directions. The net force exerted on the body is: \[ F_{\text{net}} = F_1 - F_2 \] Step 3: Computing Net Power Multiplying the net force by velocity: \[ P_{\text{net}} = (F_1 - F_2)v \] Thus, the correct answer is: \[ (F_1 - F_2)v \]