review of FORCES

Two people pulling a rope with equal force in opposite directions, and the rope does not move.

One person pulling a rope harder than the other, causing the rope to move.

A ball rolling down a hill.

A car accelerating on a highway.

Balanced forces are equal in strength and opposite in direction, while unbalanced forces are not equal in strength or not opposite in direction.

Balanced forces always move objects, while unbalanced forces never move objects.

Balanced forces are always stronger than unbalanced forces.

Unbalanced forces are always weaker than balanced forces.

balanced

unbalanced

balanced

unbalanced

balanced

unbalanced

balanced

unbalanced

30 N

6 N

18 N

12 N

By adding the strengths of the forces

By multiplying the strengths of the forces

By subtracting the strengths of the forces

By dividing the strengths of the forces

Force pairs

Balanced forces

Unbalanced forces

Frictional forces

For every action, there is an equal and opposite reaction.

An object in motion stays in motion unless acted upon by a force.

Force equals mass times acceleration.

Objects at rest remain at rest unless acted upon by a force.

A) A box is sliding across the floor at a steady speed

B) A hockey puck is changing its direction as it hits the boards

C) A race car is taking a curve while maintaining a constant speed.

D) a bicyclist is coasting to a complete stop on a flat road

The ball continued moving in the same direction, and its speed increased.

The ball continued moving in the same direction, and its speed decreased.

The ball changed directions, and its speed increased

The ball changed directions, and its speed stayed the same.