Question

1. a car is sitting at a stop light. when the light turns green, the car accelerates for 2.8 s and reaches a final velocity of 15 m/s. what is the average acceleration of the car?

Explanation:

Step1: Recall acceleration formula

The formula for average acceleration is $a=\frac{v - u}{t}$, where $v$ is final velocity, $u$ is initial velocity, and $t$ is time. The car starts from rest, so $u = 0\ m/s$, $v=15\ m/s$ and $t = 2.8\ s$.

Step2: Substitute values

Substitute $u = 0\ m/s$, $v = 15\ m/s$ and $t=2.8\ s$ into the formula $a=\frac{v - u}{t}$, we get $a=\frac{15 - 0}{2.8}$.

Step3: Calculate the result

$a=\frac{15}{2.8}\approx5.36\ m/s^{2}$

Answer:

$5.36\ m/s^{2}$