Question

a car traveling at a speed of 24 m/s comes to a stop at a red light. how much time will it take for the car to stop if its acceleration is -8.0 m/s²? 3 s 16 s 32 s 192 s

Explanation:

Step1: Recall the kinematic equation

We use the kinematic equation \( v = v_0 + at \), where \( v \) is the final velocity, \( v_0 \) is the initial velocity, \( a \) is the acceleration, and \( t \) is the time.
Given: \( v_0 = 24\ m/s \), \( v = 0\ m/s \) (since the car comes to a stop), \( a = -8.0\ m/s^2 \).

Step2: Rearrange the equation to solve for \( t \)

From \( v = v_0 + at \), we can rearrange it to \( t=\frac{v - v_0}{a} \).
Substitute the given values: \( t=\frac{0 - 24}{-8.0} \).

Step3: Calculate the time

First, calculate the numerator: \( 0 - 24=-24 \).
Then, divide by the acceleration: \( t = \frac{-24}{-8.0}=3\ s \).

Answer:

3 s (corresponding to the option "3 s")