Question

A block of mass 4 kg is kept on a rough horizontal surface as shown in figure. A horizontal force of 19.6 N is just able to slide the block (a) Find the coefficient of static friction. (b) If a force of 16 N acts then what is the frictional force acting on the block?

• A. (a) 0.5 (b) 3.6N
• B. (a) 1.5 (b) 3.6N
• C. (a) 0.5 (b) 4.6N
• D. (a) 1.5 (b) 4.6N

Answer 1

The correct option is A (a) 0.5 (b) 3.6N

$F-f=m\times 0$

$f=19.6=\mu N$

$19.6=\mu \left(4g\right)$

$\mu =\frac{19.6}{4\times 9.8}=0.5$

b) if another force$F^{\prime }$ of 16 N is applied;

$F-F^{\prime }-f=0$

$19.6-16-f=0$

$f=3.6N$