Answer to Question #87831 in Mechanics | Relativity for Ma

Question

A car is initially travelling at 5.0ms-1. It then speeds up, accelerating at 1.2 ms-2 for 4.0 seconds. What is the cars final velocity?

Answer 1

We can find the car's final velocity from the kinematic equation:

$$v_f = v_i + at,$$

here, $v_i = 5.0 ms^{-1}$ is the initial velocity of the car, $v_f$ is the final velocity of the car, $a = 1.2 ms^{-2}$ is the acceleration of the car and $t = 4.0 s$ is the time during which the car accelerates.

Then, we get:

$$v_f = v_i + at = 5.0 \dfrac{m}{s} + 1.2 \dfrac{m}{s^2} \cdot 4.0 s = 9.8 \dfrac{m}{s}.$$

Answer:

$v_f = 9.8 \dfrac{m}{s}.$