Question

A driver in a car traveling at a speed of 21.8m/s sees a cat 101 m away on the road. How long will it take for the car to accelerate uniformly to a stop in exactly 99 m.

Answer 1

The acceleration of the car will be needed in order to calculate the time. It is important to consider that the final speed is equal to zero:


`v^2 = v_0^2 + 2ad\ \to\ a = (-v_0^2)/(2d) = -(21.8^2\ m^2/s^2)/(2\cdot 99\ m) = -2.4(m)/(s^2)`

We can clear time in the speed equation:


`v = v_0 + at\ \to\ t = (-v_0)/(a) = (-21.8\ m/s)/(-2.4\ m/s^2) = \bf 9.08\ s`

If you find some mistake in my English, please tell me know.

Answer 2

It will take 9.08 s for the car to accelerate uniformly to a stop in exactly 99m. I am hoping that this answer has satisfied your query and it will be able to help you in your endeavor, and if you would like, feel free to ask another question.