Notes: Forces

Force- A push or a pull exerted on an object.

Forces can affect motion in several ways: → start moving → move faster → move slower → stop moving → change direction → change shape

FORCE FACTS: → Forces are measured in Newtons (N) with a tool called a spring scale. → Forces usually act in pairs → Forces act in a particular direction → Forces usually cannot be seen, but their effects can

Forces and Direction: More than one force can act on an object at a time. The forces can push or pull in any direction. What happens to the object when the forces act depends on two things: → How strong the forces are → The direction of the forces

Net Force: The overall force on an object when all the individual forces acting on an object are added together.

Calculating Net Force: To find the net force when forces are acting in the same direction, simply add them together. 30 N to the right 10 N to the right 30 N + 10 N = 40 N

Calculating Net Force: To find the net force when forces are acting in opposite directions, simply subtract the smaller force from the larger force. 10 N to the left 30 N to the right 30 N – 10 N = 20 N to the right 30 N to the left 10 N to the right 30 N - 10 N = 20 N to the left

Balanced Force: Equal forces acting on an object in opposite directions. When a net force is zero, the forces are balanced. Balanced forces DO NOT cause changes in motion.

Unbalanced Force: A nonzero net force that changes an object’s motion. When a net force is greater than zero, the forces are unbalanced.

Friction- a force that opposes motion between two surfaces that are touching.

Work- the action that results when a force causes an object to move in the direction of the force.

Inertia- the tendency of all objects to resist any change in motion.