Question

a car moves with a speed of 30km/h in half of the total time taken and with 40km/h rest of the time. what is the avarege speed of the body ?​

Answer 1

speed=distance*time

let total time taken be t

case 1:

d1=30*t/2

d1=15t

d2=40*t/2

d2=20t

distance/time=speed

d1/t=15 m/s

d2/t=20 m/s

average speed=total distance/total time

=>d1+d2/t=15+20/2

d/t=>35/2=17.5 m/s

hope it helps