# Time Distance Speed Calculations Distance Speed Time Units

- Slides: 7

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 Write as a fraction compared with 60 minutes (in an hour) 30 = 0. 5 hrs 30 minutes 60 15 minutes 15 = 0. 25 hrs 60 Hours to minutes Multiply by 60 2 hours 2× 60 = 120 mins 0. 75 hours 0. 75× 60 = 45 mins

Time Distance Speed Calculations Distance = Speed × Time Units of Measure: Distance: Speed: Kilometres Miles Metres Kilometres per hour Miles per hour Metres per second Means ÷ km/hr miles/hr 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 60 80 × 15 60 42 × 10 60 4. 80 miles per hour for 15 minutes 5. 42 km per hour for 10 minutes 20 km 20 miles 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 : 240 = 60 km per hour 1. A train travels 240 km in 4 hours 4 What is its average speed? 2. A plane flies over two cities that are 63 miles apart. The journey takes 7 minutes. What is its average speed? 63 = 9 miles per minute Answer in miles per minute 7 3. An athlete can run 100 metres in 12 seconds. Calculate the 100 = 8. 3 m per second athlete’s speed. Answer in metres per second and 1 d. p. 12 4. A cheetah took 6 seconds to run 150 m. 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 400 = 50 seconds How long did he take? 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 4 km. Find how long he takes in minutes. 3 = 0. 75 hrs 0. 75× 60 = 45 mins 4 4. A cyclist travelled 6 km at 18 kmph. Find how long he takes in minutes. 6 = 0. 3 hrs 0. 3× 60 = 20 mins 18 . .

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 0. 8× 60 = 48 mins 25 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