Chapter 5 - Turning Effect of Forces

What is the moment of a force?

• The sum of the forces and the perpendicular distance from the

  pivot to the line of action of the force.

• The product of the forces acting on the opposite direction of the pivot.

• The product of the force and distance from the pivot to the line of action of the force.

• The product of the force and the perpendicular distance from the  pivot to the line of action of the force.

What is the unit used for moment?

• N/m

• Nm

• Ncm

• N

Which of the following is not required to obtain the moment of a force?

• The distance between the forces.

• The direction of the force.

• The magnitude of the force.

• The position of the pivot.

A horizontal pole is attached to the side of a building. There is a pivot P at the wall and a chain is connected from the end of the pole to a point higher up the wall. There is a tension F in the chain.

Which of the following length represent the perpendicular distance between the pivot and the line of action of tension F?

• d

• h

• l

• s

A 5 N weight was attached to a meter rule as shown. What is the moment due to the 5N force?

• 450 Nm

• 300 Nm

• 150 Nm

• 0 Nm

Which of the following statements about an object in equilibrium is incorrect?

• The object moves at constant speed.

• Principle of moment can be applied.

• The resultant force is zero.

• The resultant moment is zero.

A uniform beam is pivoted at the 50 cm mark. Two forces are acting on it as shown

If the beam is balanced, which of the following A, B, C and D indicates the likely position and direction of the third force?

• A

• B

• C

• D

What is meant by centre of gravity of a body?

• The centre position of a body.

• The moment produced by the weight of the body.

• The weight acting at the center of the body.

• The point through which its whole weight appears to act.

A lamina of uniform thickness was suspended freely by a pin. Which position represent the centre of gravity of the lamina?

• A

• B

• C

• D

The diagram shows the cross-sections of different glass container. Which one is the most stable when filled with a liquid to the brim?

• A

• B

• C

• D