Question

1. a car traveling west in a straight line on a highway decreases its speed from 30.0 meters per second to 23.0 meters per second in 2.00 seconds. the cars average acceleration during this time interval is a) 3.5 m/s² east b) 3.5 m/s² west c) 13 m/s² east d) 13 m/s² west

Explanation:

Step1: Recall acceleration formula

The formula for average acceleration is $a=\frac{v_f - v_i}{t}$, where $v_f$ is the final velocity, $v_i$ is the initial velocity, and $t$ is the time - interval.

Step2: Identify the values

$v_i = 30.0\ m/s$ (west), $v_f=23.0\ m/s$ (west), and $t = 2.00\ s$.

Step3: Calculate the acceleration

$a=\frac{v_f - v_i}{t}=\frac{23.0 - 30.0}{2.00}\ m/s^2=\frac{- 7.0}{2.00}\ m/s^2=-3.5\ m/s^2$. The negative sign indicates that the acceleration is in the opposite direction of the initial velocity. Since the car is moving west and the acceleration is negative, the acceleration is $3.5\ m/s^2$ east.

Answer:

A. $3.5\ m/s^2$ east