Uniform Linear Motion Model: Force

Physics 1: Section 2.3

What forces are considered Action-at-a-distance?

Gravitational force and electric force

What forces are considered contact forces?

Push or pull force, normal force, static friction force

What is tension force?

A contact force transmitted through a rope, string, or similar that is always along its length

What is the symbol and SI units for tension force?

FT and newton

What is kinetic friction force?

A force on a system that is parallel to the contact surface with a surrounding when the system is sliding relative to the surrounding and directed such as to impede this sliding

What is the symbol and SI units for kinetic friction force?

FK and newton

What is inertia?

The tendency of matter to resist changes to its motion

What does constant velocity mean?

Constant speed in a straight line

No speeding up, slowing down, or changing direction

Why is the motorized cart moving with the constant velocity among the track?

Net force is 0 → Newtons first law

Which explanation correctly describes why a person suffers a frontal lobe concussion when his forehead hits an immovable surface? Note that the skull stops, but the brain continues to move forwards until it strikes the skull.

The brain continues at a constant velocity because the net force briefly remains zero

When is the uniform linear motion model appropriate?

When the system is moving at constant velocity, the speed is constant, and moved along a straight line