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 with 60 minutes (in an hour) Multiply by 60 30 60 30 minutes = 0.5 hrs 2 hours 2× 60 = 120 mins 15 60 15 minutes = 0.25 hrs 0.75 hours 0.75× 60 = 45 mins

Time Distance Speed Calculations Distance = Speed × Time Units of Measure: Distance: Kilometres Miles Metres Means ÷ Speed: Kilometres per hour km/hr km/hr Miles per hour miles/hr Metres per second m/s The calculation is given by the units of measure Distance Time Speed =

Time Distance Speed Calculations Distance = Speed × Time D = S × T Use this formula to find the distances for: 20 miles per hour for 2 hours 60 miles per hour for 4 hours 40 kmph for 30 minutes 80 miles per hour for 15 minutes 42 km per hour for 10 minutes 20 × 2 40 miles 60 × 4 240 miles 40 × 30 60 20 km 80 × 15 60 20 miles 42 × 10 60 7 km

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 : A train travels 240 km in 4 hours What is its average speed? 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 3. An athlete can run 100 metres in 12 seconds. Calculate the athlete’s speed. Answer in metres per second and 1 d.p. A cheetah took 6 seconds to run 150m. How fast did it run? Answer in metres per second 240 4 = 60 km per hour 63 7 = 9 miles per minute 100 12 = 8.3 m per second 150 6 = 25 m per second

Time Distance Speed Calculations Use this formula to find : A man ran 400 m at an average speed of 8 m/s How long did he take? A coach travels 120 miles at an average speed of 40 mph. How long did it take? A walker travels a distance of 3 km at a steady speed of 4km. Find how long he takes in minutes. A cyclist travelled 6 km at 18 kmph. 400 8 = 50 seconds 120 40 = 3 hours 3 4 = 0.75 hrs 0.75× 60 = 45 mins = 0.3 hrs . 0.3× 60 . 6 18 = 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 Calculate the van’s average speed in miles per hour 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. c) Calculate the van’s average speed for the whole journey. 25 60 = 0.4167 hrs 20 0.4167 = 48 miles per hour 20 25 = 0.8 hrs 0.8× 60 = 48 mins 40 miles for (25 + 48) = 73 minutes 73 60 = 1.2167 hrs 40 1.2167 = 32.9 miles per hour