Question

A train travels at a speed of 60km /h for 0.52 at 30km /h for the next 0.24 and then at 70km/h for the next 0.71h. what is the average speed of the train

Answer 1

Thanks for asking question

in this problem first of all we have to calculate the distance travelled by the train under the three different condition of speed at the time

(1) In the first case, the train travel at the speed of 60 km / hour for a time of 0.52 hour

Now,

speed = Distance /time

so, 60= distance /0.52

and, Distance = 60×0.52 = 31.2km_______(i)

(2) in the second case the train travel at the speed of 30 km/ hour for a time of 0.24 hour

Now, speed = distance /time

so, 30= distance /0.24

and, distance = 30×0.24 = 7.2km_______(ii)

(3) in the third case, train travel at the speed of 70 km / hour for a time of 0.71 Hour

Again = speed = distance /time

so, 70= distance /0.71

and, distance = 70×0.71 = 49.7km_______(III)

Now, from the question (1),(2)and (3) we get:

Total distance traveled = 31.2+7.2+49.7
= 88.1km

and, Total time taken = 0.52+0.24+0.71 = 1.47

We know that :

Average of speed = Total distance travelled / total time taken

=> 88.1/1.47

=> 59.9km/h

I hope it's help you

Regards: Brainly leader

Answer 2

According to the question we know that

(I) In the first case the train travel at the speed of 60 km / hour for a time of 0.52 hour

Now,

speed = Distance /time

Distance = 60×0.52 = 31.2km........(1)

(ii) in the second case the train travel at the speed of 30 km/ hour for a time of 0.24 hour

distance = 30×0.24 = 7.2km........(2)

(iii) in the third case, train travel at the speed of 70 km / hour for a time of 0.71 Hour

distance = 70×0.71 = 49.7km..........(3)

from the equation first, second and third we get

Total distance = 88.1km

Total time taken = 1.47

so,

Average of speed= 59.9km/h

I hope it's help you