A device that can change the direction of a force is called a machine. It may be very simple, such as a lever. This can change a force pushing down on one end of the lever into a force pushing up on an object at the other end of the lever. A bicycle is able to move along because the crankshaft changes the force of your feet pushing down into the turning force of the wheels going round.
An applied force affects the motion of an object. An applied force can be a push, pull, or dragging on an object. The push can come from direct contact, like when objects collide or from a force field like magnetism. The pull seems to only come from a field at a distance, like gravity or magnetism. Dragging can occur when sliding an object over the surface of another.
The action from a force can cause an object to move or speed up (accelerate), to slow down (decelerate), to stop, or to change direction. Since any change in velocity is considered acceleration, it can be said that a force on an object results in the acceleration of an object.
When a force acts on an object that is stationary or not moving, the force will cause the object to move, provided there are no other forces preventing that movement. If you throw a ball, you are pushing on it to start its movement. If you drop an object, the force of gravity causes it to move.
If an object is initially stationary, it accelerates when it starts to move. Acceleration is the change in velocity over a period of time. The object is going from v = 0 to some other speed or velocity. Likewise, if an object is already moving and a force is applied in the same direction, the object will speed up or accelerate. For example, a gust of wind can speed up a sailboat.
A force applied at an angle to the direction of motion of an object can cause it to change direction. A side wind will cause an airplane to change its direction.
It is possible that the object keeps going at the same speed, if the force is applied perpendicular to the direction of motion. But the velocity of the object changes. Speed is how fast the object is going, while velocity is speed plus direction.
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