Question

A cross-country skier can complete a 7.5 km race in 45 min. What is the skier’s average speed?

Answer 1

Answer

2.7778 m/s

Explanation

Speed is rate of change of distance with time.

It is the distance covered in a unit time.  SI units of speed in m/s. Other units are Km/h, knots e.t.c

Average speed  = (total distance covered) / (total time taken)

                             = 7.5 Km / 45 Min

                             =  1/6 Km/Min

Or,

7.5Km = (7.5 × 1000) m = 7500 m

45 min = 45 × 60 2700 seconds

Average speed = 7500/2700

                           = 2.7778 m/s

Answer 2

To calculate for the average speed, we simply divide the total distance covered by the time it takes to travel that distance. In this case, we simply divide 7.5 km with 45 min. Therefore, the skier's average speed is 0.1667 km/min. Hope this helps.