Top Banner
Speed Objectives 1.3 recall and use the relationship between average speed, distance moved and time: average speed = distance moved/time taken STARTER TASK 1.What is the formula for calculating speed? 2.What is meant by ‘Average Speed’? 3.A car travels 70km at an average speed of 35km/hr. How long was the journey? Give
20

Speed Objectives 1.3 recall and use the relationship between average speed, distance moved and time: average speed = distance moved/time taken STARTER.

Mar 26, 2015

Download

Documents

Welcome message from author
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
Page 1: Speed Objectives 1.3 recall and use the relationship between average speed, distance moved and time: average speed = distance moved/time taken STARTER.

Speed Objectives1.3 recall and use the relationship between average speed, distance moved andtime: average speed = distance moved/time taken

STARTER TASK1.What is the formula for calculating speed?2.What is meant by ‘Average Speed’?3.A car travels 70km at an average speed of 35km/hr.  How long was the journey? Give units.

Page 2: Speed Objectives 1.3 recall and use the relationship between average speed, distance moved and time: average speed = distance moved/time taken STARTER.

What are the units of speed when:

1.Distance is measured in metres and time in seconds

2.Distance is measured in miles and time in hours

3.Distance is measured in kilometres and time in hours

4.Distance is measured in metres and time in minutes

5.Distance is measured in millimetres and time in seconds

Page 3: Speed Objectives 1.3 recall and use the relationship between average speed, distance moved and time: average speed = distance moved/time taken STARTER.

Speedspeed = distance

time

In physics speed is usually measured in:metres per second (m/s)

Page 4: Speed Objectives 1.3 recall and use the relationship between average speed, distance moved and time: average speed = distance moved/time taken STARTER.

also:distance =

and:time =

speed time

distance

speed x time

distance speed

Page 5: Speed Objectives 1.3 recall and use the relationship between average speed, distance moved and time: average speed = distance moved/time taken STARTER.

6 = 12        2

What else do you know? 

2 = 12        6

12 = 6 x 2

2 = 10        5

What else do you know? 

5 = 10        2

10 = 5 x 2

5 = 15        3

3 = 15        5

15 = 5 x 3

What else do you know? 

Page 6: Speed Objectives 1.3 recall and use the relationship between average speed, distance moved and time: average speed = distance moved/time taken STARTER.

Speed = Distance                  Time

What else can you tell me?

2 = 10        5

Based on the above equation, how do I work out distance?

Based on the above equation, how do I work out time?

Distance = Speed x Time

Time = Distance ÷ Speed 

Page 7: Speed Objectives 1.3 recall and use the relationship between average speed, distance moved and time: average speed = distance moved/time taken STARTER.

Usian Bolt ran 100m in 9.58 seconds, what was his average speed?

10.43 m/s

(23 mph)

Page 8: Speed Objectives 1.3 recall and use the relationship between average speed, distance moved and time: average speed = distance moved/time taken STARTER.

Pairs of cameras spot your number plate, start a timer, and then spot your number plate again leaving a zone

800m

The speed cameras record that a car takes 350 seconds to move between them. Calculate the average speed of the car. Show your working. Give the unit.

Question 2

2.28 m/s

Page 9: Speed Objectives 1.3 recall and use the relationship between average speed, distance moved and time: average speed = distance moved/time taken STARTER.

Charlie Adam takes a free kick, He is 26 metres away  from the goal and it took 1.02 seconds before it crosses the goal line. How fast does the ball travel? 25.49 (metres / second) (x2.24 to get Miles an Hour) =

57 mph

Page 10: Speed Objectives 1.3 recall and use the relationship between average speed, distance moved and time: average speed = distance moved/time taken STARTER.
Page 11: Speed Objectives 1.3 recall and use the relationship between average speed, distance moved and time: average speed = distance moved/time taken STARTER.

http://www.metacafe.com/watch/2755153/matrix_car_chase/

Page 12: Speed Objectives 1.3 recall and use the relationship between average speed, distance moved and time: average speed = distance moved/time taken STARTER.

Activity 1

Plot these results on a speed time graph, with time on the bottom axis (the x axis) and speed on the side axis (the y axis).

Label the points where there is a change in motion A,B,C,D,E,F,H,I,J and K.

Example: point A is at time 0 and speed 0.

Page 13: Speed Objectives 1.3 recall and use the relationship between average speed, distance moved and time: average speed = distance moved/time taken STARTER.
Page 14: Speed Objectives 1.3 recall and use the relationship between average speed, distance moved and time: average speed = distance moved/time taken STARTER.

If you walk for 1 1/2 hours at an average speed of 4 miles/h. How far will you have walked?

Distance = Speed × TimeDistance = 4 × 1.5 = 6 miles

How long does it take to drive to Leeds from Blackpool (85 Miles) if you travel at an average speed of 60 mph?

Time = Distance ÷ Speed Time = 85 ÷ 60 = 1 Hour and 41 Minutes 

Page 15: Speed Objectives 1.3 recall and use the relationship between average speed, distance moved and time: average speed = distance moved/time taken STARTER.

1 meter per second = 2.23693629 (2.24) mph. 

So, take meters per second and multiply by 2.23693629 (2.24) to get miles per hour. 

Example, 55 meters per second = 123.03 mph.1m/s = 2.2369mph

Read more: http://wiki.answers.com/Q/How_do_you_convert_meters_per_second_into_miles_per_hours#ixzz1IZCtHIRh

http://www.youtube.com/watch?v=MeCadjzVNZ8

Page 16: Speed Objectives 1.3 recall and use the relationship between average speed, distance moved and time: average speed = distance moved/time taken STARTER.

To work out the speed of an object you need to know:      Distance, time and speed

the distance travelled; how long it took to travel that distance.

Page 17: Speed Objectives 1.3 recall and use the relationship between average speed, distance moved and time: average speed = distance moved/time taken STARTER.

A boy takes 1 hour to travel from his home to the cinema, a distance of 10 km. Calculate his average speed in km/h.

d

s x t

Cover the quantity to be calculated - s (speed)

= 10 km/h

      Speed calculation example

10 km1 h

=

d (distance in km)average speed (in km/h) t (time in h)

=

Page 18: Speed Objectives 1.3 recall and use the relationship between average speed, distance moved and time: average speed = distance moved/time taken STARTER.

3600 s10,000 m=

= 2.8 m/s

Sometimes the units have to be changed in a speed calculation. Here is the same problem but with different units:

1x60x60

      Speed calculation example – units check 

A boy takes 1 hour to travel from his home to the cinema, a distance of 10 km. Calculate his average speed in m/s.

d (distance in m)average speed (in m/s) t (time in s)=

d

s x t

Cover the quantity to be calculated - s (speed)

Page 19: Speed Objectives 1.3 recall and use the relationship between average speed, distance moved and time: average speed = distance moved/time taken STARTER.

= 3.6 km/h  x  2 h

distance (km) = speed (km/h) x time (h)

Question 1 A group set off from home and walk at an average speed of 3.6 km/h. How far would they travel in two hours? Give your answer in km.

d

s x t

      Speed calculation – question 1

= 7.2 km

Page 20: Speed Objectives 1.3 recall and use the relationship between average speed, distance moved and time: average speed = distance moved/time taken STARTER.

10 km5.4 km/h

=

Question 1 How long would it take a woman to walk 10 km if her average speed is 5.4 km/h ? 

d

s x t

time =distance

speed

      Speed calculation – question 1

= 1.85 hours