Question

A man travels 100m due to east with constant speed 20 m/s he stop for 5sec and then returns back among the same route with constant speed 10m/s .calculate average speed and average velocity​

Answer 1

To find the average speed, always remember this formula,

Avg. Speed = TDT/TTT

where TDT= total distance travelled

and. TTT= Total time taken

Now, first he travels 100m and then he comes back 100m , so, in total he travels 200m.

Hence, TDT=200 m

Again, to find the total time,

He is going with 10m/s, it means he travels 10m in 1 second, so he will take 10 seconds to travel 100m, so T1=10 s

Stoppage time T2= 5 s.

For coming back, he travels 20 m in one second, so he will take 5 s to travel 100m, so T3=5 s.

Now, TTT= T1+T2+T3=10+5+5=20s.

Therefore, putting these values in above formula, we get avg. Speed as 10 m/s.