Question

A vehicle is moving on a road with an acceleration $a=20m/s^2$ as shown in the figure. The frictional coefficient between the block of mass $m$ and the vehicle so that block does not fall downward is (g = 10 $m/s^2$)

• A. 0.5
• B. 0.4
• C. 2
• D. 0.7

Answer 1

The correct option is A 0.5

$f=\mu ma$

$f=mg=\mu ma$

$g=\mu a$

$\mu =\frac{g}{a}$$=\frac{10}{20}=0.5$