Speed, distance, and time

Question 1

What is speed?

Answer 1

The distance that a moving object covers each second.

Question 2

What is the equation to calculate average speed?

Answer 2

average speed (m/s) = total distance travelled (m) / total time taken (s)

a = d/t

Question 3

What does a diagonal line on a distance/time graph tell you about the speed?

Answer 3

Constant or steady.

Question 4

What is the equation to calculate speed?

Answer 4

speed (m/s) = change in distance (m) / time taken (s)

s = d/t

Question 5

What does a curved inwards line on a distance/time graph tell you about the speed?

Answer 5

Accelerating.

Question 6

What does a curved outwards line on a distance/time graph tell you about the speed?

Answer 6

Decelerating.

Question 7

What does a horizontal line on a distance/time graph tell you about the speed?

Answer 7

Stationary.

Question 8

On a distance/time graph, does a steep line represent a faster or slower speed than a shallower one?

Answer 8

Faster.

Question 9

On a distance/time graph, which axis does time go on?

Answer 9

The x axis.

Question 10

1)Calculate the speed for each part of the journey:

A = 0 - 60 s, 0 - 80 m

B = 60 - 120 s, 80 - 80 m

C = 120 - 140 s, 80 - 240 m

2) Calculate the average speed for the whole journey.

Answer 10

1)
A = 80 m / 60 s = 1.33 m/s

B = 0 m / 60 s = 0 m/s

C = 160 m / 20 s = 8 m/s

2) average speed = 240 m / 140 s = 1.7 m/s

Question 11

Calculate the average speed of a motorbike that travels 120 m in 8 s.

Answer 11

speed = 120 m / 8 s, speed = 15 m/s

Question 12

A car accelerates from 0 m/s to 12 m/s in 5 s. Sketch a distance/time graph to show this.

Answer 12

gradient of zero at origin, increasing gradient of graph shown, distance and time shown as correct y- and x-axes, respectively.

Question 13

The speed limit for a car on a motorway in the UK is 112.7 km/h. Calculate this speed in m/s.

Answer 13

112.7 km = 112,700 m; 1 hour = 60 x 60 = 3600 s

112,700 m / 3600 s = 31.3 m/s