Question

When the driver presses the brake pedal, his car stops with an acceleration of - 8.7 m/s. How far will the car travel while coming to a complete stop if its initial speed is 10 m/s? A. 10.2 m B. 13.1 m C. 9.5 m D. 5.7m

Answer 1

D. 5.7 m

Step-by-step explanation:

The acceleration of the car is -8.7 m/s² and the car has an initial speed (u) of 10 m/s. The car said to come to rest, that means that the final velocity (v) of the car is 0 m/s.

To find the distance traveled by the car (s) before complete stop, this equation is being used:

v² = u² + 2as

`2as=v^2-u^2\\s=(v^2-u^2)/(2a)\\ Substituting:\\s=(0-10^2)/(2*-8.7)\\ s=(-100)/(17.4)\\ s=5.7\ m`

The car traveled 5.7 m before coming to a complete stop