• Push or a pull applied on an object • A result of the interaction between objects that can cause changes in their motion • In the absence of _____, the object stays at rest and the objects that are in motion continue to be in motion. • Without _____, an object does not change its state of motion

• Force

• Contact Force

• Non-Contact Force

• Net Force

• Applied Force

Forces that result when the two interacting objects are perceived to be physically contacting each other ▪ Contact is needed for the force to act on an object ▪ Examples: ▪ Normal force ▪ Tension and Compression ▪ Friction

• Force

• Contact Force

• Non-Contact Force

• Net Force

• Applied Force

▪ Action-at-a-distance forces ▪ Forces that result even when the two interacting objects are not in physical contact with each other, yet are able to exert a push or pull despite their physical separation ▪ Examples ▪ Gravitational forces ▪ Electrostatic forces ▪ Magnetic Forces

• Force

• Contact Force

• Non-Contact Force

• Net Force

• Applied Force

• When there is more than one force acting on an object, the combination of all those forces is called the _____ (_____). • It is the _____ that changes an object’s state of motion. • The resulting motion of the object depends on the magnitude and direction of the t acting on it.

• Force

• Contact Force

• Non-Contact Force

• Net Force

• Applied Force

❑ a force exerted on an object ❑ Added if they are acting in the same direction ❑ Subtracted if they are applied in different directions ❑ May cause an object to change their state of motion

• Force

• Contact Force

• Non-Contact Force

• Net Force

• Applied Force

❑ A contact force that serves to slow down a moving object or prevent motion altogether ❑ Parallel to the surfaces in contact ❑ Opposite the direction of motion

• Friction

• Static Friction

• Kinetic Friction

• Normal Force

• A frictional force which keeps the object at rest • Keeps stationary objects from sliding against each other • Without _____, walking or running would not be possible.

• Friction

• Static Friction

• Kinetic Friction

• Normal Force

• Slows down motion • Causes loss of energy due to heat • Causes wear and tear of moving machine parts •

• Friction

• Static Friction

• Kinetic Friction

• Normal Force

frictional force when an object is sliding in motion

• Kinetic Sliding Friction

• Kinetic Rolling Friction

frictional force when an object is rubbing surfaces while rotating

• Kinetic Sliding Friction

• Kinetic Rolling Friction