time distance speed by 9M0qQk

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									                Time Distance Speed Calculations

                      Distance = Speed × Time
Units of Measure:
       Time:        Hours
                    Minutes
There are 60 minutes in an hour so convert these times in
minutes to hours (in decimal notation).

      Minutes to hours                   Hours to minutes
 Write as a fraction compared       Multiply by 60
 with 60 minutes (in an hour)
 30 minutes        30 = 0.5 hrs
                   60               2 hours      2× 60 = 120 mins

 15 minutes         15 = 0.25 hrs   0.75 hours 0.75× 60 = 45 mins
                    60
                Time Distance Speed Calculations

                    Distance = Speed × Time
Units of Measure:
       Distance:    Kilometres
                    Miles
                    Metres                               Means ÷
       Speed:       Kilometres per hour       km/hr
                    Miles per hour            miles/hr
                    Metres per second         m/s

  The calculation is given by the units of measure

                Speed =    Distance
                            Time
               Time Distance Speed Calculations

                    Distance = Speed × Time

                           D=S×T
Use this formula to find the distances for:

1. 20 miles per hour for 2 hours              20 × 2      40 miles

2. 60 miles per hour for 4 hours              60 × 4     240 miles

3. 40 kmph for 30 minutes                     40 × 30     20 km
                                                   60
4. 80 miles per hour for 15 minutes           80 × 15     20 miles
                                                    60
5. 42 km per hour for 10 minutes              42 × 10      7 km
                                                    60
              Time Distance Speed Calculations

                 Distance = Speed × Time
Using what we have learnt from rearranging equations

                 If D = S × T
       then         D =S×T


        and         D =S×T
               Time Distance Speed Calculations

                     Speed = Distance
                               Time
Use this formula to find :
1. A train travels 240 km in 4 hours       240 = 60 km per hour
   What is its average speed?               4
2. A plane flies over two cities that are 63 miles apart.
   The journey takes 7 minutes. What is its average speed?
Answer in miles per minute                 63 = 9 miles per minute
                                           7
3. An athlete can run 100 metres in 12 seconds. Calculate the
   athlete’s speed.                        100 = 8.3 m per second
Answer in metres per second and 1 d.p. 12
4. A cheetah took 6 seconds to run 150m. How fast did it run?
Answer in metres per second                150 = 25 m per second
                                            6
               Time Distance Speed Calculations

                     Time = Distance
                              Speed
Use this formula to find :
1. A man ran 400 m at an average speed of 8 m/s
   How long did he take?                 400 = 50 seconds
                                           8
2. A coach travels 120 miles at an average speed of 40 mph.
   How long did it take?                120 = 3 hours
                                         40
3. A walker travels a distance of 3 km at a steady speed of 4km.
Find how long he takes in minutes. 3 = 0.75 hrs
                                     4           0.75× 60 = 45 mins
4. A cyclist travelled 6 km at 18 kmph.
                                             .
   Find how long he takes in minutes. 6 = 0.3 hrs
                                       18
                                                   .
                                                   0.3× 60 = 20 mins
               Time Distance Speed Calculations


    A delivery van sets off at 07:45 to deliver a package 20 miles
    from the store. It arrives at the customer at 08:10

    a) Calculate the van’s average speed in miles per hour
                 25 = 0.4167 hrs     20 = 48 miles per hour
                 60                0.4167
    The van’s average speed on the return journey is 25 mph.

    b) How long does the return journey take?
    Give your answer in minutes. 20 = 0.8 hrs
                                     25          0.8× 60 = 48 mins
    c) Calculate the van’s average speed for the whole journey.
40 miles for (25 + 48) = 73 minutes
                       73 = 1.2167 hrs     40 = 32.9 miles per hour
                       60               1.2167

								
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