Question

A body of mass $10 kg$ is moving with an initial speed of $20 m / s$ The body stops after $5 s$ due to friction between body and the floor The value of the coefficient of friction is: (Take acceleration due to gravity $g =10 ms ^{-2}$ )

• A. $0.2$
• B. $0.4$
• C. $0.5$
• D. 0.3

Answer 1

Answer: (B)

$0.4$

Answer 2

$a=-\mu g$
$\because v=u+at$
$0=20+(\mu\times10)\times5$
$50\mu=20$
$\mu=\frac{2}{5}$
=0.4
Therefore , the value of coefficient of friction is 0.4
So , the correct option is (B) : 0.4