Question

A body travels half a distance with the
speed of 20 m/s and the other half with
the speed of 30 m/s.The average speed
of the body is

Answer 1

Let the total distance be 2x.
For first half distance :
Speed is 20 m/s
Thus time taken t
1
​
=
20
x
​

For second half distance :
Speed is 30 m/s
Thus time taken t
2
​
=
30
x
​

Average velocity V
avg
​
=
t
1
​
+t
2
​

2x
​

⟹ V
avg
​
=
20
x
​
+
30
x
​

2x
​
=
20+30
2×20×30
​
=24 m/s

Answer 2

Answer:

24 m/s

Explanation:

Let the total distance be 2x.

For first half distance :

Speed  is 20 m/s

Thus time taken   t1=20x

For second half distance :

Speed  is 30 m/s

Thus time taken   t2=30x

Average velocity   Vavg=t1+t22x

⟹ Vavg=20x+30x2x=20+302×20×30=24 m/s