Coefficient of limiting friction and its determination - Jamb Physics Past Questions and Answers

Question 6:

• JAMB 1989

A block of mass m is held in equilibrium against a vertical wall by a horizontal force. If the coefficient of friction between the wall and the block is µ, the minimum value of the horizontal force is

A. µmg
B. (1-µ)mg
C. (1+µ)mg
D. Mg/µ

Question 7:

• JAMB 1990

A body of mass 10kg rests on a rough inclined plane whose angle of tilt \(\theta\) is variable. \(\theta\) is gradually increased until the body starts to slide down the plane at 30^o. The coefficient of limiting friction between the body and the plane

A. 0.30
B. 0.50
C. 0.58
D. 0.87

Question 8:

• JAMB 1992

In the diagram above, the hanging mass m2 is adjusted until m1 is on the verge of sliding. The coefficient of static friction between the mass m1 and the table is

A. M1/m2
B. M1g/m2
C. M2/m1
D. M2g/m1

Question 9:

• JAMB 1994

Calculate the magnitude of the force required to just move a 20kg object along a horizontal surface if the coefficient of friction is 0.2. [g = 10ms^-2]

A. 400.0N
B. 40.0N
C. 4.0N
D. 0.4N

Question 10:

• JAMB 2002

A bead travelling on a straight line wire is brought to rest at 0.2 by friction. If the mass of the bead is 0.01kg and the coefficient of friction between the bead and the wire is 0.1, determine the work done by the friction
[g = 10ms\(^2\)]

A. 2 x 10\(^{-4}\)
B. 2 x 10\(^{-3}\)
C. 2 x 10\(^{-1}\)
D. 2 x 10\(^2\)