Moments and equilibrium of rigid bodies Quiz

1. Find the moment of a $20$ N force about a point at perpendicular distance $0.5$ m from its line of action.

• A. $40$ N m
• B. $20.5$ N m
• C. $10$ N m
• D. $0.025$ N m

2. A uniform beam of length $4$ m and weight $60$ N rests horizontally on supports at its two ends. Find the reaction at each end.

• A. $60$ N
• B. $30$ N
• C. $20$ N
• D. $120$ N

3. A ladder rests against a smooth vertical wall. What force does the wall exert on the ladder?

• A. A horizontal normal reaction and an upward friction force
• B. A vertical force only
• C. Friction only, acting up the wall
• D. A horizontal normal reaction only

4. A uniform horizontal rod $AB$ of weight $40$ N and length $2$ m is hinged at $A$ and held by a vertical string at $B$. Find the tension.

• A. $20$ N
• B. $40$ N
• C. $10$ N
• D. $80$ N

5. A ladder is in limiting equilibrium with the ground. Friction $F$ and normal reaction $R$ satisfy

• A. $F<\mu R$
• B. $F>\mu R$
• C. $F=\mu R$
• D. $F=R$