Question

A block is placed on a rough horizontal plane ($xz-$ plane) with coefficient of friction is equal to $\mu$. In $Y$ and $Z$ direction constant force mg is applied as shown, and in the $X-$ direction a time-varying force $F=mgt$ is applied, where $t$ is time. If block starts moving at time $t=1s$. Then value of $\mu$ is:

• A. $\frac{1}{2}$
• B. $\frac{1}{\sqrt{2}}$
• C. $\frac{1}{\sqrt{3}}$
• D. $\frac{1}{3}$

Answer 1

Answer: (A)

$\frac{1}{2}$

At $t=1$sec

$F=mg$

So,

$mg=\mu mg+\mu mg\mu =0.5$