SPEED
8.What two units of measurement are necessary for describing speed?
distance and time




9.Distinguish speed in general from instantaneous speed.Give an example.
Speed-a measure of how fast something is moving.
Instantaneous speed-the speed that something has at any one instant.
example is the electric current in an electric meter


10.What is the average speed of a horse that gallops a distance of 15km a time of 30 min?
average speed=total distance covered / time interval
15km/30 min=0.5 ave. speed km/30 min


11.How far does a horse travel if it gallops at an average speed of 25 km/h for 30 min?
12.5 km/hr for 30 min