Moment of forces

What is the unit of moment?

• Nm

• Nm^-1

• Ns

• Ns^-1

The centre of mass of regular shape is along the line of symmetrical body (point of symmetry). The centre of mass of regular shape is along the line of symmetrical body (point of symmetry)

• less than W

• more than W

• W

• impossible to tell

Four table lamps are shown along with the position M of the centre of mass in each case. M Which lamp is the most stable?

• A

• B

• C

• D

What is the weight of the beam?

• 2.0 N

• 3.0 N

• 3.3 N

• 5.0 N

A metal cone with a circular base is placed on a flat surface. The stability of the cone depends on

• its weight only.

• the diameter of its base and the position of its centre of mass.

• the diameter of its base only.

• the position of its centre of mass only.

Forces are applied to a uniform beam pivoted at its centre. Which beam is balanced?

• A

• B

• C

• D

If a nut and bolt are difficult to undo, it may be easier to turn the nut by using a longer spanner. This is because the longer spanner gives ...

• a larger turning moment.

• a smaller turning moment.

• less friction.

• more friction.

Which object is in equilibrium?

• A

• B

• C

• D

A beam is pivoted at its centre of mass. It is acted upon by two forces, 10 N and 5.0 N, as shown. What is the resultant moment about the pivot?

• 175Ncm anticlockwise

• 1755Ncm clockwise

• 25Ncm anticlockwise

• 25Ncm clockwise

The diagrams show three uniform beams P, Q and R, each pivoted at its centre. The two forces acting on each beam are also shown. Which beams rotate clockwise?

• A

• B

• C

• D