FrictionMedium
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
A block of mass M = 5 kg is resting on a rough horizontal surface for which the coefficient of friction is 0.2. When a f...A block of mass m is placed on a surface with a vertical cross-section given by y =. If the coefficient of friction is 0...A block of mass 1 kg is stationary with respect to a conveyer belt that is accelerating with 1 m/s2 upwards at an angle ...In the figure, a ladder of mass m is shown leaning against a wall. It is in static equilibrium making an angle θ wi...A body initially at rest and sliding along a frictionlesstrack from a height h (as shown in the figure) just completes a...