Distance, Speed and Time

 

        

 

Distance travelled, average speed maintained and time elapsed are related by the following:

 

or, as used in Science classes

 

Remember : Converting time units

Times decimal of hour by 60 to  get minutes:
1.15hrs means 1hr 9 minutes, not 1 hr 15 minutes,
since 0.15 x 60 = 9 not 15

 

Divide minutes by 60 to get decimal of hour: 
3hrs 45 minutes  = 3.75 hours , not 3.45 hours,
since 45/60 = 0.75 not 0.45

 

To convert from kilometres per hour to metres per second

since there are a thousand metres in a kilometre , sixty seconds in a minute and sixty minutes in an hour.

 

To convert from metres per second to kilometres per hour

 

To convert from miles to kilometres

 

To convert from kilometres to miles

or

Distance travelled

Examples

A man walks for 3 hours at a speed of 3 miles per hour.
How far has he travelled ?

 

A man walks for 45 minutes at a speed of 4 miles per hour.
How far has he travelled ?

Convert the minutes into hours :

so

      

 

Average Speed maintained

 

Examples

A man covers a distance of 21 miles in 7 hours.
Calculate his average speed.

 

A man covers a distance of 232 miles in 7 hours and 15 minutes.
What was his average speed ?

Convert the minutes into hours :

so

 

Time taken

 

Examples

How long does it take an aircraft  travelling at 580 km per hour to travel a distance of 232 kilometres ?

convert to minutes

 

A man drove a distance of 250 miles at an average speed of 70 mph.
How long did the journey take ?
Give your answer in hours, minutes and seconds.

convert to minutes

convert to seconds

 

DST graphs