Measuring speed: practical | Starter Quiz | Oak National Academy

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.

Answer explanation

Ball B took less time to cover the distance, that means it is travelling at a higher speed than ball A. Ball B is moving faster than ball A.

Which of these are units for speed?

• m

• m/s

• km/h

• N/s

• s/m

Answer explanation

The correct units for speed are m/s (metres per second) and km/h (kilometres per hour).

Tags

NGSS.MS-PS3-1

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.

Answer explanation

As average speed is given by speed = distance ÷ time, only the distance and time are needed to find the speed.

Tags

NGSS.MS-PS3-1

Five swimmers complete a 200 m race. Their finish times are shown. Starting with the fastest, put the racers in order of average speed.

• swimmer C: 606 s

• swimmer D: 610 s

• swimmer A: 620 s

• swimmer E: 600 s

• swimmer B: 612 s

Answer explanation

The shorter the time, the greater the average speed. The order is E, C , D, B and finally A.

Tags

NGSS.MS-PS3-1

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

Answer explanation

The distance travelled is given by: distance = speed × time, so distance = 2 m/s × 30 s.

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NGSS.MS-PS3-1

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

Answer explanation

The solution is: speed = distance ÷ time, speed = 800 m ÷ 125 s = 6.4 m/s

Tags

NGSS.MS-PS3-1