Moment of a force - Jamb Physics Past Questions and Answers

Question 6:

• JAMB 1982

A Uniform beam PQ of mass 20kg and length 5m is balanced as shown above, a man of weight 800N stands at M such that QM = 2m. The reaction at P and Q respectively are(take g = 10ms^-2)

A. 300N and 500N
B. 420N and 580N
C. 220N and 380N
D. 580N and 420N
E. 382N and 220N

Question 7:

• JAMB 1985

Two masses 40g and 60g respectively, are attached firmly to the ends of the light meter rule. The center of gravity of the system is

A. At the mid-point of the meter rule
B. 40cm from the lighter mass
C. 40cm from the heavier mass
D. 60cm from the heavier mass
E. Indeterninate because the meter-rule is light

Question 8:

• JAMB 1986

A uniform meter rule QR is balanced on a knife edge which is 55cm from R, when a mass of 10g is hung at P as shown above, the mass of the meter rule is

A. 550g
B. 350g
C. 70g
D. 35g

Question 9:

• JAMB 1990

Two horizontal forces, 10N and 8N and another force F1 inclined at 30 to the vertical acting as shown in the diagram above, keep the body P in equilibrium, The weight of the body is

A. 2√3/3N
B. √2N
C. 4√3/3
D. 2V3N

Question 10:

• JAMB 1995

A uniform rod PQ of length 1m and mass 2kg is pivoted at the end p. If load of 14N is placed at the center of the rod, find the force that should be applied vertically upwards at Q to maintain the rod at equilibrium horizontally [g = 10ms^-2]

A. 68N
B. 28N
C. 17N
D. 7N