Question

If a car covers 2/5th of total distance with v1 speed and 3/5th distance with v2. Find average speed

Answer 1

Let the distance to be covered = 5 units.

Fraction of the journey covered at v speed= 2/5.

Distance covered at v speed = 2 units

Time taken to cover 2 units at v = 2/vunits of time

Fraction of journey covered at v' speed= 3/5

Distance covered at v’speed= 3 units.

Time taken to cover 3 units at v'= 3/v’units of time.

Total time taken to cover 5 units of journey= (2/v)+(3/v')= (2v’ + 3 v)/vv'

Average speed = total distance covered ÷ total time taken = 5 ÷ ( 2v’ + 3 v)/vv'= 5 v v'/ (2v’ + 3v)