Question

55. Two cars are moving in the same direction with a
speed of 30 km/h. They are separated from each
other by 5 km. Third car moving in the opposite
direction meets the two cars after an interval of
4 minutes. The speed of the third car is
(1) 30 km/h
(2) 25 km/h
(3) 40 km/h
(4) 45 km/h​

Answer 1

Solution:

Note: This is a question related to relative motion.

Now:

$\bullet$ Let the two cars moving in same direction be A and B and the third car be C.

$\bullet$ Let the velocity of C be 'u'.

So:

Velocity of C with respect to B would be:

$\implies$ u + 30 (As they are moving in opposite directions.)

So:

The speed u + 30 would be given by:

$\implies$ 5/(4÷60) = u + 30

$\implies$ 5 × 60/4 = u + 30

$\implies$ 75 = u + 30

$\implies$ u = 45 km/h

Therefore:

Correct option: (4) 45 km/h

__________________

Answered by: Niki Swar, Goa❤️