moment Flashcards
What is the moment of a force, and how is it used in everyday life?
The moment of a force is a measure of its turning effect. Everyday examples include opening a door, using a wrench, or turning a spanner.
State the formula for the moment of a force.
A: Moment = Force × Perpendicular Distance from the Pivot.
What does the principle of moments state for an object in equilibrium?
The principle of moments states that for an object in equilibrium, the sum of the clockwise moments about any pivot is equal to the sum of the anticlockwise moments
What is one experimental setup to verify the principle of moments?
Suspend a uniform meter rule horizontally using a pivot and hang weights at different points on both sides. Adjust the positions of the weights until the meter rule balances, and check if the sum of clockwise and anticlockwise moments are equal.
How does the perpendicular distance from the pivot affect the moment of a force?
Increasing the perpendicular distance increases the moment for the same force, making the turning effect greater.
What are the SI units for the moment of a force?
The SI unit for the moment of a force is Newton meter (Nm).
Why is the handle of a spanner longer when loosening a tight bolt?
A longer handle increases the perpendicular distance from the pivot, increasing the moment for the same applied force, making it easier to turn the bolt.
How does the principle of moments apply to a lever in equilibrium?
The force applied on one side of the lever times its distance from the pivot is equal to the force exerted on the other side times its distance from the pivot.
A 5 N force is applied 0.2 m away from a pivot. Calculate the moment of the force.
Moment = Force × Perpendicular Distance = 5 N × 0.2 m = 1.0 Nm.
Describe how you would determine if a meter rule is balanced using the principle of moments in an experiment.
- Suspend the meter rule at its midpoint.
Add known masses to either side at varying distances.
Adjust positions until the rule is horizontal.
Record the forces and distances, and verify that the sum of clockwise moments equals the sum of anticlockwise moments.
A student finds that the meter rule tilts even when moments are balanced. What could be the reasons?
Possible reasons include the meter rule being non-uniform, inaccurate measurements of distances, or weights not being aligned perpendicular to the rule.
If a uniform beam is balanced horizontally on a pivot with a 2 kg weight hanging 1 m from the pivot on one side, what weight must be placed 0.5 m from the pivot on the other side?
Moment on one side = 2 kg × 10 N/kg × 1 m = 20 Nm.
To balance, Moment on the other side = 20 Nm.
Weight = Moment ÷ Distance = 20 Nm ÷ 0.5 m = 40 N (or 4 kg).
