24/01/2016 Measuring Average Speeds Method Collect a metre stick and a stopwatch. Mark out and measure a distance and time how long it takes to cover this distance. COPY Groups of 2 or 3.

Results transport method Distance (m) Time (s) Average Speed (m/s) Walking Sprinting 3 Legged(optional) Hopping Blind Walk

Average Speed tells us how much distance is covered in a certain time. To measure average speed we need to measure –Distance (d) metres (m) or kilometres (km) –Time (t) second (s) hour (h) metres per second (m/s or ms -1 ) kilometres per hour (km/h or kmh -1 ) Unit of Average Speed (v) Average Speed

Measurements –Distance travelled can be measured using a metre stick or trundle wheel or tape,…. –Time is measured using a stop watch. Metres per second or m/s or ms -1 Metres or m Seconds or s Remember : 1 km = 1000 metres 1 hr = 60 x 60 = 3600s In physics the units normally used for average speed are: m/s (or ms -1 ) km/h (or kmh -1 ) Calculations COPY 24/01/2016

Example 1 A car travels from London to Glasgow (550 miles) in 7 hours. a)What is the average speed of the car in m.p.h.? d = 550 miles t = 7 hours v = ?

b)For a stretch of this journey the car is travelling at 100 km/h. What is this in m/s? d = 100km t = 1 hour = m = 60 x 60 = 3600s v = ?

Open up your notes at page 1, note 1, Average speed, and collect a highlighter or coloured pen. time metre stopwatch

d v t m s ms -1

v = ? d = = 280 m t = 100 s v = d t = = 2.8 ms -1

Nat 5 Problems Page 2, Questions Int 2 Problems, Page 32, Questions 1 - 8