Question

7. A car moves through 20 km at a speed of 40 km/h,
and the next 20 km at a speed of 60 km/h. Calculate
its average speed​

Answer 1

Answer:

48kmph

Explanation:

1st case:

d= 20km

s1= 40kmph

2nd case:

d=20km

s2= 60kmph

for equal distance...

Avg.speed= 2/((1/s1)+(1/s2))

= 2/((1/40)+(1/60))

=(2*120)/5

=240/5

=48 kmph