Question

If a car starts from rest and accelerates at 4.20 m/s2 for 5.00 s, what will be the car's average velocityduring this time in meters per second?

Answer 1

Given,

The acceleration of the car, a=4.20 m/s²

The time period, t=5.00 s

The car starts from the rest, ∴ the initial velocity, u=0 m/s

According to the equations of motion, the final velocity is calculated as,

$v=u+at$

On substituting the known values in the above equation,

$v=4.20\times5.00=21.00\text{ m/s}$

The average velocity at a constant acceleration is calculated as,

$v_a=\frac{(v-u)}{2}$

Therefore the average velocity is,

$v_a=\frac{21.00-0}{2}=10.50\text{ m/s}$

Therefore the average velocity of the car is 10.50 m/s