Force (physics)
A force is a power that changes or may produce change of movement in a body on which it acts or presses. It changes the state of rest or uniform motion of an object.A force can start or stop the motion of an object.
A force can change the speed of an object.
A force can change the direction of the motion of the object.
A force, if acted acted in the direction the same as that of the motion of an object, can increase the speed of the object.
A force, if acted in the direcction opposite to that of the motion of an object, can decrease the speed of the object.
A force, if it is large enough and acted in the direction opposite to that of the motion of an object, can make an object go backwards.
Besides affecting the motion of an object, a force can also change the shape of an object.
A force can also be used to balance another force to prevent movement.
Non-contact forces can act on an object at a distance, e.g. the force exerted by a magnet and the force of gravity.
Forces can be measured by a spring balance.
The unit of force is the Newton, written as N.