Question

1. a skateboarder slows down from 12 m/s to 4 m/s in 2 seconds. what is the acceleration? (hint: your answer will be negative.)

Explanation:

Step1: Identify velocities and time

Initial velocity $v_i=12\ \text{m/s}$, final velocity $v_f=4\ \text{m/s}$, time $\Delta t=2\ \text{s}$.

Step2: Calculate velocity change

$\Delta v = v_f - v_i = 4 - 12 = -8\ \text{m/s}$.

Step3: Compute acceleration

$a = \frac{\Delta v}{\Delta t} = \frac{-8}{2} = -4\ \text{m/s}^2$.

Answer:

$-4\ \text{m/s}^2$