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
What does the principle of moments state for an object in rotational equilibrium?
The sum of clockwise moments equals the sum of anticlockwise moments
What is the mechanical advantage of a lever?
Load force divided by effort force
Which arrangement describes a second-class lever?
The load lies between the pivot and the effort
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
Which distance is used when calculating the moment of a force?
The perpendicular distance from the pivot to the force's line of action
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
In a lever system, what is the effort?
The force applied to operate the lever
Which arrangement describes a third-class lever?
The effort lies between the pivot and the load
How can the turning effect of a fixed force about a pivot be increased?
Apply the force farther from the pivot
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
What is the moment about a pivot if a force's line of action passes through the pivot?
Zero
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
Which arrangement describes a first-class lever?
The pivot lies between the effort and the load
What is a couple in mechanics?
Two equal, opposite, parallel forces acting along different lines