Question

The distance between kanpur & jaipur is 90 km.A started from jaipur with 5 kmph and b started from kanpur with 3 kmph.B increases his speed 1.5every hour.When will they meet?

Answer 1

Given conditions ⇒

Speed of the A =  5 km/hr.

Speed of the B = 3 km/hr.

Acceleration of B = 1.5 km/hr²

Acceleration of A = 0

Now,

$S_A + S_B = 90$

∴ 5t + 3t + 1/2 × 1.5 × t² = 90

⇒ 8t + 0.75t² = 90

∴ 0.75t² + 8t - 90 = 0

On solving this quadratic equation we will get,

 t = 6.9 seconds. ≈ 7 seconds.

Hope it helps.