Question

A car is moving at a constant speed of 14 m/s when the driver presses down on the gas pedal and accelerates for 14 s with an acceleration of 1.8 m/s 2 . what is the average speed of the car during the period?

Answer 1

acceleration of car is 1.8 m/s^2

time = 14 s

initial speed = 14 m/s

so the final speed is calculated by

$v_f = v_i + at$

$v_f = 14 + 14 * 1.8$

$v_f = 39.2 m/s$

so the total distance moved in this interval of time is

$d = \frac{v_f + v_i}{2}* t$

$d = \frac{39.2 + 14}{2}* 14$

$d = 372.4 m$

now the average speed is given as

$v = \frac{d}{t}$

$v = \frac{372.4}{14}$

$v = 26.6 m/s$

so the average speed will be 26.6 m/s