Question

In a 100 meter race A beats B by 20 meter or 5sec .Find the speed of A?​

Answer 1

Answer:

When A completes 100m, B is at 80m which is 20m behind.

Now A beats B by 4 secs. This means B takes 4 more seconds to complete the race

As B is 20m behind when A completes the race, so B takes 4 secs to complete 20m

SB = 5m/s

Total time of B = 100/5 = 20 secs

Time of A = 20 - 4 = 16 seconds

Thus, SA = 100/16 = 6.25m/s (Answer)