Question

On the horizontal surface of a truck ($\mu =0.6$), a block of mass $1kg$ is placed. If the truck is accelerating at the rate of $5m/se{c}^2$ then frictional force on the block will be

• A. $5N$
• B. $6N$
• C. $5.88N$
• D. $8N$

Answer 1

Answer: (A)

$5N$

If the block has to move, it should overcome static frictional force which is $\mu mg=0.6\times 10=6$N

As the truck is moving with an acceleration, a pseudo force acts on the block which is ma=$1\times 5=5$N

As this force is not enough for the block to move, an equal frictional force acts in the opposite direction which is equal to 5N