FrictionHard
Question
Given mA = 30 kg, mB = 10 kg, mC = 20 kg. Between A and B friction coefficient m1 = 0.3, between B and C driction coefficient μ2 = 0.2 and between C and ground μ3 = 0.1. The least horizontal force F to start the motion of any part of the system of three blocks resting upon one another as shown in figure is (g = 10 m/s2)
Options
A.60 N
B.90 N
C.80 N
D.150 N
Solution
(A) Limiting friction between A & B = 90 N
Limiting friction between B & C = 80 N
Limiting friction between C & ground = 60 N
Since limiting friction is least between C and ground, slipping will occur at first between C and ground. This will occur when F = 60 N.
Limiting friction between B & C = 80 N
Limiting friction between C & ground = 60 N
Since limiting friction is least between C and ground, slipping will occur at first between C and ground. This will occur when F = 60 N.
Create a free account to view solution
View Solution FreeMore Friction Questions
Given in the figure are two blocks A and B of weight 20 N and 100 N, respectively. These are being pressed against a wal...A block on a long table is tied by massless ropes to two hanging blocks as in figure. Initially block C is moving downwa...A block of mass M is pulled along a horizontal friction surface by a rope of mass m. If a force P is applied at the free...A system is shown in the figure, which is released from rest. There is no friction between ground and mass 5m. The coeff...A system consists of three masses m1, m2 and m3 connected by a string passing over a pulley P. The mass m1 hangs freely ...