Measuring speed: practical | Science | Quizalize & Oak National Academy

Starter quiz

Two balls roll the same distance; ball A takes 4 s and ball B takes 3 s. Which statements are correct?
- Ball A was moving faster than ball B.
- Ball A was moving slower than ball B. ✓
- Ball A has a greater average speed than ball B.
- Ball A has a lower average speed than ball B. ✓
Which of these are units for speed?
- m
- m/s ✓
- km/h ✓
- N/s
- s/m
Which pieces of information are needed to find the average speed of a toy car rolling across a desk?
- The mass of the toy car.
- The time it takes the toy car to travel. ✓
- The height of the desk.
- The distance the toy travels. ✓
- The size of the forces on the car.
Five swimmers complete a 200 m race. Their finish times are shown. Starting with the fastest, put the racers in order of average speed.
- 1
  
  ⇔
  
  swimmer E: 600 s
- 2
  
  ⇔
  
  swimmer C: 606 s
- 3
  
  ⇔
  
  swimmer D: 610 s
- 4
  
  ⇔
  
  swimmer B: 612 s
- 5
  
  ⇔
  
  swimmer A: 620 s
A bus is travelling at 2 m/s and moves for a time of 30 s. Which of these shows how to calculate the distance the bus has travelled?
- distance = 2 m/s + 30 s
- distance = 2 m/s × 30 s ✓
- distance = 2 m/s ÷ 30 s
- distance = 30 s ÷ 2 m/s
- distance = 30 s - 2 m/s
A skater in a race travels a distance of 800 m in a time of 125 s. Calculate their speed.
- 0.16 m/s
- 1.6 m/s
- 6.4 m/s ✓
- 675 m/s
- 925 m/s

Exit quiz

Match the key words to the explanations.
- dynamics trolley
  
  ⇔
  
  A wheeled object used to investigate motion. ✓
- gradient
  
  ⇔
  
  A measure of the steepness of a slope or ramp. ✓
- timer
  
  ⇔
  
  A device used to measure time. ✓
- metre rule
  
  ⇔
  
  A device used to measure length. ✓
- average speed
  
  ⇔
  
  Overall distance travelled divided by overall time taken. ✓
Which feature of a dynamics trolly allows it to roll without slowing down much?
- The wheels have low friction. ✓
- It is very light.
- It is very heavy.
- It produces its own driving force.
Which of these measures should be taken to accurately measure the time it takes for a dynamics trolley to roll between two points on a ramp?
- The ramp must have a high gradient (be steep).
- Look directly across the finish line. ✓
- Push the trolley at the start.
- Look along the ramp from the start to the finish line.
- Start the trolley rolling with a countdown. ✓
A dynamics trolley is rolled a distance of 1.5 m, taking 3.0 s to cover the distance. What is the average speed of the trolley?
- 0.5 m/s ✓
- 2.0 m/s
- 3.5 m/s
- 2.5 m/s
- 4.5 m/s
A dynamics trolley is released on ramps with different gradients and is found to have a greater average speed on the steepest ramp. Which of these statements help explain the results?
- The ramp is producing a force on the trolley which speeds it up as it rolls. ✓
- The forces on the trolley are always balanced.
- The greater the gradient, the smaller the resultant force acting on the trolley.
- The greater the gradient, the larger the resultant force acting on the trolley. ✓
- The frictional force keeps the trolley moving.
A student times a trolley rolling 1.00 m down a ramp three times. The times were 3.24 s, 3.44 s and 3.36 s. Calculate the average speed of the trolley.
- 0.13 m/s
- 0.30 m/s ✓
- 1.0 m/s
- 3.33 m/s
- 30.0 m/s

Worksheet

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Video

Lesson Details

Key learning points

A ramp will produce a force that allows a dynamics trolley to roll down it.
The average speed of the trolley can be found from distance and time measurements.
Counting down ‘3, 2, 1, go’ helps start a stopwatch at the right moment.
Observing with eyes in line with the finish line helps stop a stopwatch at the right moment.

Common misconception

Pupils may think that the constant force on the trolley will cause it to move at a constant speed.

Demonstrate that the trolly speeds up as it rolls, by finding speed near the start and near the end of the ramp.

Keywords

Dynamics trolley - A small wheeled object used to investigate movement.
Gradient - The steepness of a slope, the larger the gradient the steeper a slope is.
Timer - A device used to precisely measure time, usually to 0.1 s or 0.01 s.
Metre rule - A simple length measuring instrument.
Average speed - The overall distance travelled divided by the overall time for a journey.