Question

The body with an initial velocity of
18 km/hr.its acceleration is 9 m/s²
over a distance of 200m Calculate
final velocity of the body in m/ sec
​

Answer 1

To Find :

Final velocity in m/s

Solution :

Initial velocity , u = 18 km/h

⇒ u = 18 × ⁵/₁₈ m/s

⇒ u = 5 m/s

Acceleration , a = 9 m/s

Distance , s = 200 m

Final velocity , u = ? m/s

Apply 3rd equation of motion ,

$:\implies \sf \pink{v^2-u^2=2as}\ \; \bigstar$

$:\implies \sf v^2-(5)^2=2(9)(200)$

$:\implies \sf v^2-25=3600$

$:\implies \sf v^2=3600+25$

$:\implies \sf v^2=3625$

$:\implies \sf \green{v=60.2\ m/s}\ \; \bigstar$

Final velocity = 60.2 m/s

Answer 2

$\bf{\gray{\underbrace{\blue{GIVEN:-}}}}$

• The initial velocity of an body = 18km/hr

• It's acceleration = 9m/s²

• It covered a distance = 200m

$\bf{\gray{\underbrace{\blue{TO\:FIND:-}}}}$

• The final velocity .

$\bf{\gray{\underbrace{\blue{SOLUTION:-}}}}$

$\orange\bigstar\:\bf{\pink{\overbrace{\underbrace{\purple{v^2\:-\:u^2\:=\:2as\:}}}}}$

Where,

• v = final velocity

• u = initial velocity

• a = acceleration

• s = distance

✨ According to the question,

• u = 18km/h = 18 × 5/18 = 5m/s

• a = 9m/s²

• s = 200m

➳ $\bf\gray{v^2\:-\:5^2\:=\:2\times{9}\times{200}\:}$

➳ $\bf\pink{v^2\:-\:25\:=\:3600\:}$

➳ $\bf\blue{v^2\:=\:3600\:+\:25\:}$

➳ $\bf\orange{v\:=\:\sqrt{3625}\:}$

➳ $\bf\green{v\:=\:60.2\:m/s\:}$

$\red{\therefore}$ The final velocity of the body is "60.2m/s" .