Turning Forces, Centre Of Gravity

Question 1

A lever

Answer 1

Is any rigid body which is free to turn about a fixed point called the fulcrum

Question 2

Examples of levers

Answer 2

Door, door handle, pliers, scissors, metre stick, screwdriver (used to open paint tin) etc.

Question 3

Law of the lever

Answer 3

Stated that when a lever (e.g. A metre stick) is balanced, the total clockwise moments equal the total anti-clockwise moments

Question 4

Central of gravity

Answer 4

Of an object is the point through which all the weight of the object appears to act. (I.e. The centre of its weight)

Question 5

Stable equilibrium

Answer 5

Is present if when an object is slightly tilted, it’s centre if gravity is raised, and it goes back to the original position on release

Question 6

Unstable equilibrium

Answer 6

Is present if when an object is slightly tilted its centre of gravity is lowered, and it takes a new position when released (I.e. It falls over on its side)

Question 7

Neutral equilibrium

Answer 7

Is present if when an object is moved its centre of gravity is neither raised nor lowered. The object never becomes unstable- it does not fall over and just takes up a new position where if is still in neutral equilibrium.

Question 8

Moment

Answer 8

Of a force is the turning effect of a force

Moment=force x distance from the fulcrum