U6: Time & Speed

Key Learning Points:

(A) Time

• Time is like the name given to any moment. E.g. 4.45p.m., 9.45a.m. etc
• It is fixed at any one time
• It can be written in the 12 hour clock or 24 hour clock
• In the 24 hour clock, 0000 is midnight, that is, the start of a new day. Thus in the 24 hour clock format, the time starts from 0000 to 2359.
• Duration is a measurement of how much time an activity takes. E.g. 1h, 5h 30 min, 45s, 38min etc
• NEVER add or subtract time and duration together as they are 2 different things! E.g. 1.45pm + 15min = 2pm WRONG!!>
• When dealing with time and duration, always draw a timeline to represent your workings

(B) Speed

• This means how fast an object or person is travelling at any unit (1) time
• Distance = Speed x Time
  
• Before you apply the formula, always make sure that the units of each of the above parts are 'talking' to each other.
• Meaning to say, if speed is given as km/h, make sure that the distance must be in 'km' and time in 'h'. (Do the necessary conversions e.g. 1km = 1000m and 1h = 60min)
• After solving for the answer, double check that your answer has the same unit as what the question wants. E.g. if the question wants you to give time in hours, make sure you convert your time from minutes to hour.
• When finding Average Speed, find the total distance and divide it by the total time taken.

This topic is not that difficult as long as you are very careful and alert with the units and the way you present your workings. All speed questions must have these 3 parts (Distance, Speed, and Time). All you need to do is to find them, make sure the units 'talk' to each other and apply the formula and some common sense into it.