18 flashcards · Shared on 19 August 2026 by AtomAI Library
Flip each card to check yourself.
What is the moment of a force about a pivot?
The force multiplied by the perpendicular distance from the pivot to its line of action
What is the moment of a force about a pivot?
The force multiplied by the perpendicular distance from the pivot to its line of action
Which unit is used for the moment of a force?
Newton metre
A force of 20 N acts perpendicular to a lever, 0.30 m from its pivot. What moment does it produce?
6.0 N m
Which distance is used when calculating the moment of a force?
The perpendicular distance from the pivot to the force's line of action
What is the moment about a pivot if a force's line of action passes through the pivot?
Zero
What does the principle of moments state for an object in rotational equilibrium?
The sum of clockwise moments equals the sum of anticlockwise moments
A 12 N force acts 0.50 m to one side of a pivot. What force acting 0.20 m on the other side will balance it?
30 N
How can the turning effect of a fixed force about a pivot be increased?
Apply the force farther from the pivot
Why does a long spanner make it easier to turn a tight nut?
It increases the perpendicular distance from the pivot, producing a larger moment
In a lever system, what is the effort?
The force applied to operate the lever
What is the mechanical advantage of a lever?
Load force divided by effort force
For an ideal lever in equilibrium, which relationship is correct?
Effort force × effort arm = load force × load arm
A lever has an effort arm of 0.80 m and a load arm of 0.20 m. What is its ideal mechanical advantage?
4.0
Which arrangement describes a first-class lever?
The pivot lies between the effort and the load
Which arrangement describes a second-class lever?
The load lies between the pivot and the effort
Which arrangement describes a third-class lever?
The effort lies between the pivot and the load
What is a couple in mechanics?
Two equal, opposite, parallel forces acting along different lines
A couple consists of two 15 N forces whose parallel lines of action are 0.40 m apart. What is the moment of the couple?
6.0 N m