Chapter 4- Turning Effect Of Forces Flashcards
“A light metre rule…” Explain the significance of light
The rule has a very small mass and this can be ignored in the calculation. Other terms: negligible/ zero mass
When is the movement due to a non-zero force zero?
When the line of action of the force passes through the pivot
Explain the significance of the term “uniform”
All parts of the rule are similar. The c.g. of the ruler is at its center and as such, the weight of the ruler acts right through the center
Principle of moments
Principle of moments states that when an object is in equilibrium, the sum of the clockwise moments about any point is equal to the sum of the anti clockwise moments about the same point
Define center of gravity
Center of gravity of an object is defined as the point through which the entire weight of the object appears to act
Define stability
Stability is a measure of the body’s ability to return to its original position after being tilted slightly
How to increase stability
Lowering the center of gravity or
Increasing the base area
What happens to the toy when the push at point Y is removed
The c.g. shifts to the left/right of the pivot. The weight creates a clockwise/anti clockwise moment about the pivot. Therefore, the toy rotates anti clockwise/clockwise and returns to its original position
Stable equilibrium
Vertical line through its c.g. still falls within its base
Unstable equilibrium
The vertical line through its c.g. falls outside the pivot
Neutral equilibrium
The vertical line through its c.g. will always pass through its pivot
Define moment of a force (torque)
Moment of a force or torque is defined as the product of a force and the perpendicular distance from the line of action of the force to the pivot
