16-11-2012, 10:53 AM
FORCE AND SIMPLE MACHINES
FORCE AND SIMPLE MACHINES.pptx (Size: 771.32 KB / Downloads: 33)
SIMPLE MACHINES
Simple machines reduce the amount of force required to do a particular task
A force can do the following:
Move an object: A force can make a stationary objects move or make a moving object move faster(if the force applied in the direction in which the object is moving) for example a man pushing a trolley.
Stop an object from moving: A force can make a moving object slow down or stop (if the force is applied opposite to the direction in which the object is moving).
For example, a cricket player catching a ball.
Change the direction of movement: A force can change the direction in which an object is moving. For example, in football, the force applied by the player changes the direction of the moving ball.
Change the shape of an object: A force can change the shape of an object. For example, while making chapattis, the force applied hands change the shape of the dough.
Wheel and axle
Wheel and axle consists of a large wheel connected to a small rod called the axle
The wheel moves when the axle turns. The wheel and axle arrangement can be seen in machines like coffee grinder, bicycle pedal, and steering wheel of a car.
WEDGES
A sharp edge is formed when two inclined planes are placed together. This arrangement is called a Wedge.
A wedge is a simple machine used to cut or slice objects. The head of an axle and the blade of a knife are examples of a wedge.