Question

Two motorcyclists race against the clock on a 35 km cross-country route. The first cyclist travels the route with an average speed of 55 km/hr. The second cyclist starts 3.0 min. after the first but crosses the finish line at the same time. What is the average speed of the second cyclist?

a) 53.6 km/hr
b) 54.5 km/hr
c) 55.5 km/hr
d) 56.4 km/hr

Answer 1

The average speed of the second cyclist is 37.8 km/hr.

Step-by-step explanation:

To find the average speed of the second cyclist, we need to compare the time it takes for both cyclists to complete the route.

The first cyclist travels the route in t hours, since speed = distance/time, we can write the equation 55 = 35/t. Solving for t, we find t = 35/55 = 0.636 hours.

The second cyclist starts 3 minutes, or 0.05 hours, after the first cyclist and finishes at the same time, so the total time taken by the second cyclist is t + 0.05 hours.

The average speed of the second cyclist is distance/time, which can be written as 35/(t + 0.05). Plugging in the value of t, we get 37.8 km/hr as the average speed of the second cyclist.