Motion -> Jacaranda + Chapters 8 & 9

Question 1

what is a scalar quantity?

Answer 1

• A measurement of ONLY magnitude -> No direction
  = Distance, speed, time, work, energy

Question 2

What is a vector quantity?

Answer 2

• A measurement of BOTH magnitude and direction
  = Displacement, velocity, acceleration, force, impulse

Question 3

Acceleration

Answer 3

The increase or decrease of speed over a distance.
Can be either negative or positive
m/s ^-2

Question 4

Negative acceleration

Answer 4

Increasing speed in a negative direction ( + * - = - )
OR
Decreasing speed in a positive direction ( - * + = - )

Question 5

Positive acceleration

Answer 5

Increasing speed in a positive direction (+ * + = + )
OR
Decreasing speed in a negative direction ( - * - = + )

Question 6

Displacement

Answer 6

Distance travelled DIRECTLY from A to B (straight line-like)
-> An objects change in position

Question 7

Distance

Answer 7

How far it is to travel from A to B
-> Path travelled by the object, not direct distance

Question 8

Graphs for motion

Answer 8

Distance vs. Time (x-t)
Velocity vs. Time (v-t)
Acceleration vs. Time (a-t)

Question 9

The two types of forces ?

Answer 9

Contact and non-contact

Question 10

Non-contact force

Answer 10

• Caused by fields
  – Gravitational
  – Electric
  – Magnetic

Question 11

Contact force

Answer 11

• Normal force
  – Friction
  – Drag forces
  – Tension
  – Compression

Question 12

Attraction

Answer 12

Mass * gravitational pull
(a=mg)
-> 70Kg * 10 (9.8 rounded) = 700 N

Question 13

Types of everyday force

Answer 13

Force due to gravity
Friction
Normal force

Question 14

Force due to gravity

Answer 14

Fg
- Acts on every object with mass near any other object with mass

Question 15

Friction force

Answer 15

Ffr
- Essential for motion, E.g: Walking is difficult on surfaces with less friction

Question 16

Normal force

Answer 16

FN
- Contact force due to an object resting on a surface
- NOT an action-reaction pair with Fg
- “An object at rest”

Question 17

Newton’s first law

Answer 17

• Every object continues in it’s state of rest or uniform motion unless acted on by an unbalanced force

-> Law of INERTIA

Question 18

Newton’s second law

Answer 18

• The acceleration of an object as produced by a net force is directly proportional to force, and inversely proportional to mass.

-> Law of MOTION
-> Fnet = ma

Question 19

Newtown’s third law

Answer 19

• If object B applies a force on object A, then object A will apply an equal and opposite for on object B

-> F on b by a = -F on a by b