speed

Question 1

Define distance- time graph

Answer 1

It is a graph that shows how far something moved at a given time

Question 2

Define speed

Answer 2

It is the measure of how far something travelled at a given time

Question 3

Define average speed

Answer 3

It is the total distance travelled in the total time taken for a complete journey

Question 4

Define relative motion

Answer 4

It is the difference in speed between 2 moving objects or a moving and a stationary object

Question 5

What type of graph is distance-time graph

Answer 5

It is a point to point graph

Question 6

In a speed (m/s) and a time (s) graph. Which one is the independent variable and which one is the dependent

Answer 6

Independent: Time (s)
Dependent : Speed (m/s)

Question 7

What are the units of speed

Answer 7

1- Metres per second (m/s)
2- Feets per second (f/s)
3- Centimeters per second (cm/s)
4- Miles per hour (mph)
5- Kilometers per hour (kph)

Question 8

Draw the calculating speed, time and distance triangle

Answer 8

Distance ( up
speed and time ( down

Question 9

How do we calculate average speed

Answer 9

Average speed = Total distance divided total time

Question 10

What is instantaneous speed and example

Answer 10

The speed an object is moving at any time of motion

For example: the speedometer in the car

Question 11

Give an example of relative motion

Answer 11

2 moving cars

Question 12

Find the speed of these things

1- Walking fast
2- Sprinting
3- Typical speed limit
4- cheetah
5- aeroplane cruising
6- Sound in air
7-light in air

Answer 12

1- 1.7 m/s
2- 10 m/s
3- 14 m/s
4- 33 m/s
5- 255 m/s
6- 330 m/s
7- 300,000,000 m/s

Question 13

Why is it dangerous for planes to travel faster than the speed of sound?

Answer 13

The speed of sound is the maximum speed energy can be transferred through a gas. If airplanes passing that limit will cause shock waves which is very destructive and can destroy the plane.

Question 14

What are the markings on the road for?

Answer 14

The markings on the road are a fixed distance apart. A speed camera takes exactly 2 pictures 0.2 seconds apart. So they figure out the distance using the marking and the time from the camera frames to work out the speed.

Question 15

Write a guide in your book explaining to someone how to use the formula triangle.

Answer 15

To find the distance, you do speed x time.

To find the speed, you do distance divided by time.

To find the time, you do distance divided by speed.