Question

1. A train travels the first 15 km at a uniform speed of 30 km/h; the next 75 km at a uniform speed of 50 km/h; and the last 10 km at a uniform speed of 20 km/h. Calculate the average speed for the entire train journey. ​

Answer 1

Answer:

see the explanation

Explanation:

see speed = distance / time likewise,

average speed = average distance / average time

add all of the distances together

then add all speeds together

then divide both of them using the above formula I gave....

average speed = 15+75+10/30+50+20

and take the final ans

Answer 2

Given,

d

1

=15km,v

1

=30km/h

d

2

=75km,v

2

=50km/h

d

3

=10km,v

3

=20km/h

we know that,

average speed =total distance covered/total time taken

total distance covered =D=15+75+10=100km

total time taken =T=(15/30)+(75/50)+(10/20)=2.5hours

so, average speed =100/2.5=40km/h