Question

A wooden block of mass 6 kg is pulled across a rough surface by a 54 N force against a friction force \( F \). The acceleration of the block is \( 6 \, \text{m/s}^2 \). Then the value of friction force \( F \) is:

• A. 36 N
• B. 54 N
• C. 18 N
• D. 9 N

Hint:

To find the friction force, subtract the net force (from Newton's second law) from the applied force.

Answer 1

The Correct Option is A

We use Newton's second law of motion: \[ F_{\text{net}} = m \times a \] Where: - \( F_{\text{net}} = 54 - F \) (net force is the applied force minus the friction force) - \( m = 6 \, \text{kg} \) (mass of the block) - \( a = 6 \, \text{m/s}^2 \) (acceleration) Using the equation: \[ 54 - F = 6 \times 6 = 36 \] \[ F = 54 - 36 = 18 \, \text{N} \] Thus, the friction force \( F \) is \( 18 \, \text{N} \).