Answer to Question #253387 in Physics for joon

Question

A car moving at 30 m/s uniformly slows down to a speed of 10 m/s in a time of 6 seconds. Determine the acceleration of the car.

Answer 1

$$a=\dfrac{v-v_0}{t}=\dfrac{10\ \dfrac{m}{s}-30\ \dfrac{m}{s}}{6\ s}=-3.3\ \dfrac{m}{s^2}.$$

The sign minus means that the car decelerates.