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# A man is standing stationary with respect to a horizontal conveyor belt that is accelerating with $1 m/s^2$. What is the net force on the man if the coefficient of static friction between man's shoes and belt is 0.2, upto what acceleration of belt can the man continue to be stationary relative to the belt? Mass of man$=65 kg; g=9.8 m/s^2$

a)$65\; N ,\; a_0=1.96 ms^{-2}$ b)$40\; N ,\; a_0=2.62 ms^{-2}$ c)$40\; N ,\; a_0=1.96 ms^{-2}$ d)$65\; N ,\; a_0=2.62 ms^{-2}$

As the man is stationary on the belt acceleration of man=acceleration of belt
Net force on the man $=ma$
$\qquad=65 \times 1=65 N$
Coefficient of friction $\mu=0.2$
Limiting friction $=\mu mg$
For the man to be stationary with respect to belt accelerating with $'a_0'$ of belt
$ma_0=\mu mg$
$a_0=\mu g$
$\qquad=0.2 \times 9.8$
$\qquad=1.96 ms^{-2}$
Hence a is the correct answer.
edited May 27, 2014