Speed

1) When we move an object such as a ball, it will move.

2) A moving ball is either fast or slow depending its speed.

3) Speed is the rate of movement of an object.

4) The object which moves faster travels a longer distance in a given time.

Rocket has the fastest speed. (Faster time reach destination)

Car has slower speed than rocket (Slower time reach destination)

CALCULATION OF SPEED

1) Speed of a moving object can be calculate if we know the distance it has travelled and the time taken to travel the distance.

2) The units for speed are:
    a. cm per second (cm/s),
    b. metre per second (m/s),
    c. kilometre per hour (km/h).

3) The speed of an object can be calculated by using the following formula:



                             Speed  =     Distance   
                                                      Time
Example :
    a. A lorry takes three hours to reach a destination of 240 km away.

 

                             Speed =            240  

                                                        3

                                       = 80 km/j

    b. A toy car takes 2 minutes to travel a distance of 50 cm.

                             Speed =             50   

                                                        2

                                      = 25 cm/min