Question

A block of mass 1 kg lies on a horizontal surface in a truck. The coefficient of static friction between the block and the surface is 0.6. If the acceleration of the truck is $5ms^{- 2}$. The frictional force acting on the block is :

• A. 10 N
• B. 5 N
• C. 2.5 N
• D. 20 N

Answer 1

Answer: (B)

5 N

Answer 2

Limiting friction $f = \mu mg$

$= 0.6 \times 1 \times 9.8$

$= 5.88N$

Applied force, $F = ma = 1 \times 5 = 5N$

As $F < f,$ so force of friction $= 5N$