Question

A truck passes point A on a straight level road with a constant velocity of 12 m/s. At the same instant, an automobile starts from rest at point A and travels in the same direction as the truck with a constant acceleration of 1.8 m/s2. How long a time does the automobile take to pass the truck from the instant it starts at point A?

Answer 1

Answer:

$t = 13.3 s$

Explanation:

Let the car will overtake the truck after time "t" seconds

so here we can say that after time "t" seconds the distance covered by the car will be same as that of distance covered by truck

So we have

$d_{car} = d_{truck}$

so we have

$d_{truck} = 12 t$

$d_{car} = \frac{1}{2}(1.8 m/s^2) t^2$

so now we have

$12 t = 0.9 t^2$

$t = 13.3 s$