Two objects P and Q , travelling in the same direction start from rest. While the object P starts at time t = 0 and object Q starts later at t = 30 min . The object P has an acceleration of 40 km / h 2 . To catch P at a distance of 20 km , the acceleration of Q should be

Step-by-step solution

According to question, Object P starts at t = 0 and acceleration of P = 40 k m / h 2 The time taken by object P to cover 20 k m will be, s = ut + 1 2 at 2 Where, u = 0 , s = 1 2 at 2 t = 2 s a Here, a = 40 k m / h 2 and s = 20 k m t = 2 × 20 40 = 1 hour Time taken by Q will be 1 2 hour , because it started after 30 min . The acceleration in Q , a = 2 s t 2 = 2 × 20 1 2 2 = 2 × 4 × 20 = 160 k m / h 2