Friction - Jamb Physics Past Questions and Answers

Question 6:

• JAMB 1987

The coefficient of static friction between a 40kg crate and concrete surface is 0.25. Find the magnitude of the minimum force needed to keep the crate stationary on the concrete base inclined at 45o to the horizontal. [G = 10ms-1]

A. 400N
B. 300N
C. 283N
D. 212N

Question 7:

• JAMB 1988

A force, 10N, drags a mass 10kg on a horizontal table with an acceleration of 0.2ms^{[/sup]. If the acceleration due to gravity is 10ms[sup]-1}, the coefficient of friction between the moving mass and the table is

A. 0.02
B. 0.08
C. 0.20
D. 0.80

Question 8:

• 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 9:

• 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 10:

• 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