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 = (v_f + v_i)/(2)* t`

`d = (39.2 + 14)/(2)* 14`

`d = 372.4 m`

now the average speed is given as

`v = (d)/(t)`

`v = (372.4)/(14)`

`v = 26.6 m/s`

so the average speed will be 26.6 m/s