A block of mass 1 kg is placed on a truck which accelerates with acceleration \[5\,m/{{s}^{2}}\]. The coefficient of static friction between the block and truck is 0.6. The frictional force acting on the block is:
A) 5 N
B) 6 N
C) 5.88 N
D) 4.6 N
Correct Answer:
B
Solution :
The frictional force acting on the block \[f=\mu R\] but from figure, R = mg \[\therefore f=\mu mg\] Here, \[\mu =0.6,\,\,m=1\,\,kg,\,g=10\,m/{{s}^{2}}\] \[\therefore f=0.6\times 1\times 10=6\,N\] Note: Due to acceleration of truck, the block experiences a forward force \[F=ma\] Since \[f>F\], so block is not displaced from its previous position.