Topic 9 Motion

Question 1

What type of quantity is speed?

Answer 1

A Scalar Quantity

Question 2

What is the calculation for speed?

Answer 2

Speed = Distance / Time or v = s/t

Question 3

What is the equation for acceleration?

Answer 3

a = change in v / change in t

Question 4

What is the Trolley Method Steps?

Answer 4

1) Set up your apparatus as shown in the diagram. Decide where you should place your light sensor to capture the final velocity of the trolley.
2) Carefully attach the timing card to the trolley and mark a start and finish point on the ramp, at least 1 m apart.
3) Set the ramp at an angle of 5°. If you place the ramp near the edge of the bench it is easier to measure the angles.
4) Release the trolley and use the stopwatch to time the trolley down the slope.
5) Use the light gate to measure the time taken for the trolley to pass through the light gate.
6) Repeat the experiment.
7) Increase the height of the slope and repeat the experiment.

Question 5

What is distance?

Answer 5

How far an object has moved (scalar quantity).

Question 6

What is displacement?

Answer 6

Distance in a particular direction (vector quantity).

Question 7

How do you calculate speed?

Answer 7

Speed = Distance ÷ Time.

Question 8

What are the units of speed?

Answer 8

Metres per second (m/s).

Question 9

What affects the speed of walking, running, and cycling?

Answer 9

Age, fitness, terrain, and distance traveled.

Question 10

What is velocity?

Answer 10

Speed in a given direction.

Question 11

What is acceleration?

Answer 11

The rate of change of velocity.

Question 12

How do you calculate acceleration?

Answer 12

Acceleration = (Change in velocity) ÷ Time taken.

Question 13

What are the units of acceleration?

Answer 13

Metres per second squared (m/s²).

Question 14

What does a flat line mean on a distance-time graph?

Answer 14

The object is stationary.

Question 15

What does a straight diagonal line mean on a distance-time graph?

Answer 15

The object is moving at constant speed.

Question 16

How do you calculate speed from a distance-time graph?

Answer 16

Gradient = Distance ÷ Time.

Question 17

What does a curve mean on a distance-time graph?

Answer 17

The object is accelerating or decelerating.

Question 18

What does a flat line mean on a velocity-time graph?

Answer 18

The object is moving at constant velocity.

Question 19

What does a sloped line mean on a velocity-time graph?

Answer 19

The object is accelerating or decelerating.

Question 20

How do you find acceleration from a velocity-time graph?

Answer 20

Gradient = Change in velocity ÷ Time.

Question 21

How do you find distance travelled from a velocity-time graph?

Answer 21

Area under the graph.

Question 22

What is deceleration?

Answer 22

Negative acceleration (object is slowing down).

Question 23

How does changing velocity include changing speed or direction?

Answer 23

Velocity is a vector, so any change in speed or direction changes velocity.

Question 24

What factors affect thinking distance?

Answer 24

Reaction time, speed, distractions, drugs, alcohol, tiredness.

Question 25

What factors affect braking distance?

Answer 25

Speed, road condition, tyre condition, brake condition, weather.

Question 26

What is stopping distance?

Answer 26

Thinking distance + Braking distance.

Question 27

How does speed affect stopping distance?

Answer 27

Higher speed = Longer stopping distance.

Question 28

What is reaction time?

Answer 28

The time it takes for a driver to respond to a hazard.

Question 29

Typical reaction time for humans?

Answer 29

About 0.2 to 0.9 seconds.

Question 30

How can reaction time be measured?

Answer 30

Ruler drop test or computer-based test.

Question 31

What happens to braking distance if road is icy?

Answer 31

It increases greatly due to less friction.

Question 32

What happens to braking distance if tyres are worn?

Answer 32

It increases because grip is reduced.

Question 33

What is work done during braking?

Answer 33

Work done by brakes converts kinetic energy into heat.

Question 34

How is kinetic energy related to braking?

Answer 34

Greater kinetic energy = More work needed to stop.

Question 35

What is the formula for kinetic energy?

Answer 35

KE = ½ × mass × velocity².

Question 36

How does doubling the speed affect braking distance?

Answer 36

It quadruples it (because KE ∝ v²).

Question 37

What is terminal velocity?

Answer 37

When forces are balanced and object falls at constant speed.

Question 38

What are safety features in vehicles?

Answer 38

Seatbelts, airbags, crumple zones.

Question 39

How do crumple zones protect passengers?

Answer 39

Increase time taken to stop, reducing forces.

Question 40

How do seatbelts protect passengers?

Answer 40

Stretch slightly to increase stopping time and reduce forces.

Question 41

How do airbags protect passengers?

Answer 41

Spread the force over a larger area and increase stopping time.

Question 42

Why are large decelerations dangerous?

Answer 42

They produce very large forces which can cause injury.

Question 43

Equation linking force, mass, and acceleration?

Answer 43

Force = Mass × Acceleration (F = ma).

Question 44

What is uniform acceleration?

Answer 44

Constant acceleration, like an object in freefall near Earth's surface.

Question 45

What is the typical acceleration due to gravity?

Answer 45

About 9.8 m/s².