Unit 1

Question 1

Scalar and vector quantities

Answer 1

• Magnitude (number/quantity)

- Direction (up, down, left, right, north…)

Question 2

Position, distance and displacement

Answer 2

Position - vector quantity relative to a reference point
Displacement - change in position (vector quantity)\
Distance - scalar quantity based on path travelled
Distance ≥ displacement

Question 3

Algebra

Answer 3

• One direction is taken to be positive (right, up, forward, etc.) while the other is negative (left, down, backwards, etc.)
• The numbers are added together to find the net or resultant vector quantity
• The sign of the final quantity indicates the direction

Question 4

Scale Drawings

Answer 4

• Using a number line as a reference (0 position), the vectors are alined “tip to tail”
• The difference between the start point and the end point give both the magnitude and direction of the net or resultant vector quantity

Question 5

Scalar quantity

Answer 5

Speed (v)

Question 6

Vector quantity

Answer 6

Velocity

Question 7

Units

Answer 7

m/s = ms-1
km/h = kmh-1

Question 8

Formula

Answer 8

Distance / time = speed

d / t = v

Question 9

Types of Speed (or Velocity)

Answer 9

Constant
- Speed does not change
Instantaneous
- At and instant in time, speed travelling
Average
- Total distance / total time

Question 10

What is Acceleration

Answer 10

It is a change in speed:

• Speeding up (+)
• Slowing down (-)
• Changing directions

Question 11

Velocity vs. Acceleration

Answer 11

Velocity - rate at which displacement changes
- Velocity = change in displacement / change in time
Acceleration - rate at which velocity changes
- Acceleration = change in velocity / change in time
- Acceleration = (final velocity - initial velocity) / change in time

Question 12

Force

Answer 12

• Can cause a change in velocity

- Can cause a change in direction

Question 13

Average Acceleration

Answer 13

Vector quantity
- Needs units and direction
    - m/s2 = ms-2
    - km/h / 3.6 = m/s and m/s • 3.6 = km/h
Positive and negative acceleration
- Speeding up (+)
- Slowing down (-)

Question 14

Formulas

Answer 14

• vf = vi + at (no d)
• d = vit + ½ at2 (no vf)
• d = vft + ½ at2 (no vi)
• vf2 = vi2 +2ad (no t)
• d = ½(vf+vi)t (no a)

Question 15

Graphing Acceleration

Answer 15

Acceleration and d - t graphs
- Change in y / change in x = change in d / change in t = slope or velocity
Acceleration and v - t graphs
- Change in y / change in x = change in v / change in t = slope or acceleration

Question 16

v - t - d Formula

Answer 16

d / t = v

Question 17

Constant value near the surface of the earth

Answer 17

Gravity

• Has to be close to the gound
• The further you get, the weaker gravity is
• Acceleration = gravity = -9.8 m/s2

Question 18

Effect of air resistance

Answer 18

• Reduce the net (total) acceleration
• The lighter the item, the slower the acceleration
• Air resistance is the only things that affects the speed of falling, only affected by shape and size, not mass*

Question 19

Terminal velocity

Answer 19

• Maximum speed
  
  • Constant
  • Frequency and force of collision is in proportion (∝) to speed

Question 20

Vector Addition: Scale Drawings

Answer 20

Step 1: Establish your scale
Step 2: Draw the first vector, beginning at the origin (displacement or velocity). You will need to use a ruler and protractor to ensure your vector is the right length and the right direction. Ex: 20m[30º W of N]
Step 3: Draw the second vectorm again taking into account length and direction, beginning at the end of the first vector. Repeat for as many vectors as are included in the question
Step 4: Draw in the resultant (net) vector, from the start of the first vector to the end of the last vector. Measure the length (ruler) and direction (protractor) of the resultant vector. Use your scale to convert the length back into the appropriate units

Question 21

Adding Vectors: Algebra

Answer 21

Step 1: Resolve vector into x and y components
- Through the angle : COS
- Away from the angle: SIN
Step 2: Add x (horizontal) components. Add y (vertical) components. ** Pay attention to the sign (+ or -) of each vector
Step 3: Recombine x and y using the pythagorean theorem. This gives you the magnitude of the resultant vector
Step 4: Use trigonometry to determine the starting angle of the resultant vector. This gives you the direction of the resultant vector