A block of mass 1kg just remains in equilibrium with the verticle wall of a cart accelerating uniformly with \[20m/{{s}^{2}}\]as shown. The coefficient of friction between block and wall is \[(g=10m/{{s}^{2}})\]:
A) \[0.1\]
B) \[0.2\]
C) \[0.5\]
D) \[1\]
Correct Answer:
C
Solution :
For vertical equilibrium \[\Sigma {{F}_{X}}=0.R=ma\] FBD of mass, m From FBD, we get \[mg=\mu R=\mu ma\] \[\mu =\frac{g}{a}=0.5\]