Question

CODE
A car travels half of the distance with constant velocity 40 km/h and another halt with
60 km/h along a straight line. The average velocity of the car is
(1) 24 km/h
12) 48 km/h
(3) 60 km/h
(4) 40 km/h​

Answer 1

Explanation:

A car travels half of the distance with constant velocity 40 km/h and another half with 60 km/h along a straight line. The average velocity of the car is

(1) 24 km/h

(2) 48 km/h ✔

(3) 60 km/h

(4) 40 km/h

Given -

• A car travels half of the distance with constant velocity 40 Km/h
• Another half with 60 Km/h along a straight line

To Find -

Average velocity of car

Now,

As we know that

• Average velocity =

Total Distance travelled /total time taken

Let total distance travel by car is s.

Then,

Half of its distance is s/2

• Time = Distance/Speed

So,

Time taken by car to travel s/2 distance with constant velocity of 60 km/h is

= time = s/2 × 60

• = time = s/120 seconds

And

Time taken by car to travel s/2 distance with constant velocity of 40 km/h is

= time = s/2 × 40

• = time = s/80 seconds

Now,

Average velocity = s ÷ s/120 + s/80

= s ÷ 2s + 3s/240

= s ÷ 5s/240

= s × 240/5s

= 48 Km/h

Hence,

Average velocity is 48 Km/h.

Formula Used -

• Average velocity =

Total distance travelled /Total time taken