Question

A train covers half of its journey with a speed of 30mpersecond and the other half with a speed of 40mper second. calculate the speed of the train during the whole journey.

Answer 1

we take distance =x speed=d/t1 t1=d/s t1=x/30 speed=d/to t2=d/s t2=x/40 total time = t1+t2
= x/30+x/40
= 7x/120
total distance = x+x
=2x
total speed = to.d/to.t
= 2x/7x/120
=34.28 mper second square

Answer 2

The average speed of the train during the whole journey is 34.28 m/s.

Explanation:

Let the total distance covered by the train is s.

We have to calculate the average speed of the train and average speed is given as

$v_{avg} =\frac{s}{t}$

Here, s is the the total distance and t is the total time taken.

Given speed for first half journey is 30 m /s and second half is 40 m/s.

Time taken for first half,

$t_{1} =\frac{s/2}{30m/s}$

and time taken for second half,

$t_{2} =\frac{s/2}{40m/s}$

Therefore average speed,

$v_{avg} =\frac{s}{\frac{s}{60m/s}+\frac{s}{80m/s} }$

$v_{avg}=\frac{240}{7}$

       = 34.28 m/s.

Thus,  the average speed of the train during the whole journey is 34.28 m/s.

#Learn More: speed

https://brainly.in/question/3764180