Question

A car travels first 10 km in 20 minutes and another 10 km in 30 minutes. What is the average speed of the car in m/s?

Answer 1

Step 1: Given Data:

Time taken to cover first 10km=10000m, $t_1=20mint=20\times 60=1200sec$

Time taken to cover next 10km=10000m, $t_2=30mint=30\times 60=1800sec$

Step 2: Average speed of the car:

Total distance covered by car= $10000m+10000m$

= $20000m$

Total time taken by car = $t_1{+t}_2$

= $1200sec+1800sec$

= $3000sec$

Average speed,

$=\frac{totaldistance}{totaltimetaken}$

$=\frac{10000+10000}{1200+1800}$

$=\frac{20000}{3000}$

$=\frac{20}{3}m{s}^{-1}$

$=6.66m{s}^{-1}$

Thus,

Average speed of the car in m/s: $=6.66m{s}^{-1}$