Question

a man running uniformly at 8 m/s is 16 m behind a bus when it starts accelerating at 2 ms–2. Time taken by him to board the bus is  ​

Answer 1

Answer:

16 = 8t - 1/2 x 2t2 (equation relative to bus) t = 4s

Explanation:

Answer 2

Answer:

Time taken by him to board the bus is $4$ seconds.

Explanation:

Let our calculations be with respect to the bus.

Velocity of the man is given as $8m/s$

Acceleration of the bus is given as $-2m/s^{2}$

Distance to be covered is $16m$

We know the formula for distance : $s= ut+\frac{1}{2} at^{2}$

$16=8t-\frac{1}{2}$ × $2t^{2}$

$16=8t-t^{2}$

Taking every term to LHS, $t^{2}-8t+16=0$

Here we get a quadratic equation.

Solving this, we get :

$t=4$ seconds.

Hence the time taken by the man to board the bus is $4$ seconds.