Question

A boy runs for 20 min. at a unifor-
m speed of 18 km/h. At what speed should he run for the next
40 min. so that the average
speed comes 24 km/hr.​

Answer 1

Answer:

The boy should run with a speed of 27 km/h for next 40 minutes. The distance is the product of the speed and time.

Answer 2

Kinematics........... =___=

t1 = 20 min = 20/60 = 1/3 hrs

speed(1) = 18 km/h

t2 = 40 min = 40/60 = 2/3 hrs

speed (2) = ?

Average speed = 24km/h

We know the formula :-

Average speed = total speed / total time

24 = 18+x / 1/3 + 2/3

24 = 18+x /3/3

x = 24-18

x = 6 km/h

hope it helps uh!