Question

A car initially at rest starts moving with a constant acceleration of 4 m/s^2 and travels a distance of 50 m. The final velocity of the car will be​

Answer 1

Solution:

In the question 'initially at rest' means

Initial velocity (u) = 0m/s

$\space$

Acceleration (a) = 4m/s^2

Distance (s) = 50m

Final velocity (v) = ?

Using third equation of motion we have,

$\implies \underline{\boxed{\bf{ {v}^{2} = {u}^{2} + 2as}}}$

$\implies\rm{v^{2} = {0}^{2} + 2 \times 4 \times 50}$

$\implies\rm{ {v}^{2} = 2 \times 200}$

$\implies\rm{ {v}^{2} = 400}$

$\implies\rm{v = \sqrt{400} }$

$\implies\boxed{\boxed{\bf{v = 20m/s}}}$

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$\sf\underline{\underline{Some \: Important \: Equations}}$

$\sf{v = u + at}$

$\sf{s=ut+\dfrac{1}{2}}a {t}^{2}$

$\sf{ {v}^{2} = {u}^{2} + 2as}$

$\sf{v = u + gt}$

$\sf{h = ut + \dfrac{1}{2}g {t}^{2}}$

$\sf{ {v}^{2} = {u}^{2} + 2gh}$

$\underline{\rule{200pt}{4pt}}$