Distance Speed Time Saturday, 06 April 2019

Example Find the time taken for the following journeys: 100km at a speed of 20 km/h 250 miles at a speed of 50 mph 15 metres at a speed of 20 cm/s 10 000 metres at a speed of 10 m/s 𝑇𝑖𝑚𝑒= 𝐷𝑖𝑠𝑡𝑎𝑛𝑐𝑒 𝑆𝑝𝑒𝑒𝑑

Example Find the speeds of the bodies which move as follows: A distance of 600 km in 10 hours A distance of 35 km in 7 hours A distance of 45 metres in 10 seconds A distance of 500m in 10 minutes (units m/s) 𝑆𝑝𝑒𝑒𝑑= 𝐷𝑖𝑠𝑡𝑎𝑛𝑐𝑒 𝑇𝑖𝑚𝑒

Example Find the distance travelled for each of the following: At a speed of 45 mph for 2 hours At a speed of 40 km/h for 15 minutes At a speed of 15m/s for 6 seconds At a speed of 15m/s for 1 hour 𝐷𝑖𝑠𝑡𝑎𝑛𝑐𝑒=𝑆𝑝𝑒𝑒𝑑×𝑇𝑖𝑚𝑒

Calculations involving these three quantities are similar and can be easily remembered through the following triangle 𝐷=𝑆×𝑇 D 𝑆= 𝐷 𝑇 S T 𝑇= 𝐷 𝑆 Example A train travelling at an average 50 mph takes 4 hours to travel from Leeds to London. Find the distance between the two stations.

Example The Spine-tailed swift is the fastest bird in powered flight, with a top recorded speed of 171km/h. How far can the swift fly in 3 hours?

Example Virgin Atlantic flies from Manchester to Orlando, a distance of 4229 km in approximately 9 1 2 hours. Find the average speed for the whole trip

Example The cheetah is designed for running down fast prey and can reach a top speed of 113km/h. How far will a cheetah travel in 30 mins 10 mins?

Example American Quarter Horses are the fastest horses in the world. Able to run at high speeds, they can travel a quarter mile in less than 21 seconds, starting from a flat-footed standstill. What is there average speed?

Example Trent Grimsey holds the record for swimming the English Channel, a distance of 21 miles. His average speed was approximately 3 mph. How long did it take him to complete the swim?

Example In Horse racing, Hawkster covered 2.414km with an average speed of 60.86 km/h. How long did it take to complete the race?