WorksheetsMoments
Total questions: 30
Worksheet time: 1hrs 7mins
Two masses of mass 10.0 and 6.0 kg are hung from massless strings at the end of a light rod. The rod is virtually weightless. A pivot (fulcrum) is placed off center and the system is free to rotate. If the 6.0 kg mass is 4.0 m away from the pivot, how far away is the 10.0 kg mass if the system is not rotating?
0.42 m
2.4 m
4.8 m
4.2 m
Assuming the system is in equilibrium, calculate the missing distance d
3.4 m
2.8 m
4.4 m
1.6 m
The diagram shows a beam. Without any weights, the beam balances at its centre.
Three weights are hung as shown.
At which point does a load of 2 N balance the beam?
A
B
C
D
A boy of weight 600N sits on the see-saw as shown at a distance of 1.5m from the pivot. What is the force F required at the other end to balance the see-saw?
450 N
350 N
4.5 N
200 N
A moment is...
a force measured in Newtons
a turning force measured in newton metres
a distance measured in metres
a time intervals measured in clicks
Moment (Nm) =
Force (N) x distance (m)
Angular Force (N°) x distance (m)
Work done (J)
Force (N) x distance (s)
What to we call forces applied to anything that turns?
Minute
Moment
Minimum
Monument
What is the size of the moment shown by the black arrow?
30 Nm
36 Nm
40 Nm
60 Nm
State the principle of moments.
When a system is in equilibrium, the sum of the total clockwise moment is equal to the sum of the total anti-clockwise moment about the same pivot.
When a system is in equilibrium, the sum of the total clockwise moment is greater the sum of the total anti-clockwise moment about the same pivot.
When a system is in equilibrium, the sum of the total clockwise moment is less than the sum of the total anti-clockwise moment about the same pivot.
When a system is in equilibrium, the sum of the total clockwise moment is equal to the sum of the total anti-clockwise moment about the different pivot.
Two equal and oppositely directed forces acting on an object will be in equilibrium
Only if they act on the same point on the object
If they are separated by a distance
When they are balanced by a third force
when their moments about the same point are equal
What is the clockwise moment acting on this crane?
80,000Nm
100,000Nm
120,000Nm
140,000Nm
The figure below shows a man lifting a heavy rock using a steel bar. He pushes downwards on the end of the bar with a force F.
Which pivot positions allows the force F to be as small as possible?
A
B
C
D
The figure below shows a man lifting a heavy rock using a steel bar. He pushes downwards on the end of the bar with a force F.
Which pivot positions allows the force F to be as small as possible?
A
B
C
D
Explain why you choose the answer in Question 1.
A force is a applied to a long crowbar so as to move a large rock.
Which labelled arrow represents the smallest force needed to move the rock?
A
B
C
D
Explain why you choose the answer in Question 3.
A boy of weight 600N sits on the see-saw as shown at a distance of 1.5m from the pivot. What is the force F required at the other end to balance the see-saw?
300 N
600 N
900 N
1200 N
Show detailed working on how you derived your answer for Quesion 5.
A wheelbarrow can pivot about point P. The weight of the wheelbarrow, W is 200 N.
Calculate the size of the force F that is required to keep the wheelbarrow in equilibrium.
50
66.7
200 N
600 N
Show detailed working on how you derived your answer for Quesion 5.
When a mug is placed on a tabletop, a force F is required to keep it horizontal. Assume that the force exerted by the mug on the tabletop is 7.0 N.
Calculate the size of force F, that is required to keep the table top horizontal.
1 N
1.75 N
7 N
17.5 N
Show detailed working on how you derived your answer for Quesion 5.
