Question

Find the average speed in entire trip moving A to B if it moving 10m/s and coming back at a speed 20m/s.

Answer 1

since we know that,
Average speed = (total distance covered)/ total time taken .............(1)
let the distance between points A and B be S, then total distance travelled = AB + BA = S + S = 2 S
And let time t1 and t2 be taken by the object then,
t1 = AB/ VAB = S/10, &
SIMILARLY, t2 = BA / V BA = S/ 20
Now putting all values in (1), we get,

average speed = 2S / t1 + t2
Vaverage = 2S / ( s/10 + s/20)
Vav. = 2S /( 3S/20)
Vav. = 40/3 m/s
Vav. = 13.3 m/s