P2.1 Forces and Their Effects

Question 1

Define velocity.

Answer 1

Speed in a given direction.

Question 2

Define resultant force.

Answer 2

One force that replaces many forces.

Question 3

Rearrange F=ma making mass the subject.

Answer 3

m=F/a.

Question 4

When 2 bodies interact, what can you say about the size and direction of the action and reaction force?

Answer 4

Equal.

Opposite.

Question 5

What will happen to an objects motion if the resultant force is zero?

Answer 5

Stay at rest.

Or continue at a constant velocity.

Question 6

What will happen to an objects motion if the resultant force is not zero?

Answer 6

Accelerate.

Accelerate.

Question 7

State the 2 factors that will affect the acceleration of an object?

Answer 7

Size of resultant force.

Mass of object.

Question 8

How do all bodies fall in a vacuum?

Answer 8

With constant acceleration.

10m/s2 on earth.

Question 9

Describe the 3 phases of what happens to the air resistance on an object as it falls to earth?

Answer 9

Maximum acceleration, no air resistance.
Acceleration decreases, air resistance increases as speed increases.
The 2 forces balance, acceleration is zero and terminal velocity reached.