Question

the velocity of a car traveling in the positive direction decreases from 38 m/s to 30 m/s in 4.5 seconds. what is the average acceleration of the car in this process? the average acceleration of the car is m/s².

Explanation:

Step1: Recall average acceleration formula

Average acceleration is $\bar{a} = \frac{v_f - v_i}{\Delta t}$, where $v_f$ is final velocity, $v_i$ is initial velocity, $\Delta t$ is time interval.

Step2: Identify given values

$v_i = 38\ \text{m/s}$, $v_f = 30\ \text{m/s}$, $\Delta t = 4.5\ \text{s}$

Step3: Substitute values into formula

$\bar{a} = \frac{30 - 38}{4.5} = \frac{-8}{4.5}$

Step4: Calculate the result

$\bar{a} \approx -1.78\ \text{m/s}^2$

Answer:

$-1.78$