Question

A $20kg$ block is initially at rest. A $75N$ force is required to set the block in motion. After the motion, a force of $60N$ is applied to keep the block moving with constant speed . The coefficient of static friction:

• A. $0.6$
• B. $0.52$
• C. $0.44$
• D. $0.375$

Answer 1

The correct option is D $0.375$

The coefficient of static friction is given as,

$\mu =\frac{F}{mg}$

$=\frac{75}{20\times 9.8}$

$=0.3826$

Thus, the coefficient of static friction is $0.3826$.