Average speed of a biyclist

Question

 A bicyclist travels the first 800 m of a trip with a speed of 10 m/s, the next 500 m with an average speed of 5 m/s and the final 1200 m at a speed of 13 m/s. Find the average speed of the bicyclist for this trip.

Answer 1

The average speed for the entire trip is found ......total distance/total time. Remember r*t=d, so divide both sides by t and get r = d/t.

So the cyclist went 800+500+1200 m = 2500 m for total distance.

 

10t =800 leads to t=80 sec

5t=500 leads to t=100 sec

13t = 1200 leads to t = 92.3 sec

 

total time is 272.3 sec

 

Average speed for the entire trip is 2500 / 272.3 = 9.18 m/s

 

Hope this makes sense to you.