Forces and their effects GapFill

Forces can be categorised as contact or non-contact forces, depending on whether they require contact between bodies to act, or whether they act at a distance. Examples of contact forces include  friction, tension and weightfriction, air resistance and tensionair resistance, and electrostatic and gravitational forcesgravitational, electrostatic and magnetic forces, and examples of non-contact forces include  gravitational, electrostatic and magnetic forcesair resistance, and electrostatic and gravitational forcesfriction, air resistance and tensionfriction, tension and weight.

If a force does not act through the centre of an object, it may cause a  reflectionrotationmagnetic effectcrease in the object. The turning effect of a force is called a moment, which is given by the equation moment =  F²dF/dFd²Fd, where F is the force exerted and d is the distance between the point where the force acts and the pivot, which is the centre of the rotation.
If the clockwise and anticlockwise moments on an object are equal, the object  moves forwardsrotates anticlockwiserotates clockwiseis balanced.
A  momentgearpivotlever is a device used to transmit a rotational force. Often this is used to amplify the effect of a force, decreasing the force that needs to be exerted.
A  momentgearpivotlever is a rotating machine part, which changes the direction of a rotational force.