Question

A car starting from rest accelerated at a rate of 0 .5 m/s up to 2 km what would be the final velocity of the car and how much time would it take to cover 1.6​​

Answer 1

• Initial velocity=u=0m/s
• Acceleration=a=0.5m/s^2
• Distance=s=1.6m
• Final velocity=v=?

Using third equation of kinematics

$\\ \rm\longmapsto v^2=u^2+2as$

$\\ \rm\longmapsto v^2=0^2+2(0.5)(1.6)$

$\\ \rm\longmapsto v^2=1.6$

$\\ \rm\longmapsto v=\sqrt{1.6}$

$\\ \rm\longmapsto v=0.4m/s$

Now using 1st equation of motion

$\\ \rm\longmapsto v=u+at$

$\\ \rm\longmapsto t=v-u/a$

$\\ \rm\longmapsto t=\dfrac{0.4-0}{0.5}$

$\\ \rm\longmapsto t=\dfrac{4}{5}$

$\\ \rm\longmapsto t=0.8s$

Answer 2

Answer:

Using third equation of kinematics

$\begin{gathered}\\ \rm\longmapsto v^2=u^2+2as\end{gathered}$

⟼v

2

=u

2

+2as

$\begin{gathered}\\ \rm\longmapsto v^2=0^2+2(0.5)(1.6)\end{gathered}$

⟼v

2

=0

2

+2(0.5)(1.6)