Question

A car is traveling at 48 m/s, and a child runs out in front of the car 200 m away. The driver instantly applies the brakes. What acceleration must the car experience to avoid the child?

a) 6 m/s²
b) 8 m/s²
c) 10 m/s²
d) 12 m/s²

Answer 1

The car must experience an acceleration of 6 m/s² to avoid hitting the child.

Step-by-step explanation:

To avoid hitting the child, the car needs to come to a stop before reaching the child. We can use the equation:

v^2 = u^2 + 2as

where v is the final velocity (0 m/s since the car needs to stop), u is the initial velocity (48 m/s), a is the acceleration, and s is the distance (200 m). Rearranging the equation, we have:

a = (0 - 48^2) / (2 * (-200)) = 6 m/s²

Therefore, the car would need to experience an acceleration of 6 m/s² to avoid hitting the child.