Question

A car is travelling along a straight road at 8.0m/s.It accelerates at 1.0m/s 2 for a distance of 18m.How fast is it then travelling?

Answer 1

Initial velocity (u) = 8 m/s

Uniform Acceleration (a) = 1 m/s²

Distance (s) = 18 m

Final velocity (v) = ? m/s

Apply 3rd equation of motion ,

⇒ v² - u² = 2as

⇒ v² - (8)² = 2(1)(18)

⇒ v² - 64 = 36

⇒ v² = 36 + 64

⇒ v² = 100

⇒ v = 10 m/s  $\pink{\bigstar}$

More Info :

Conditions for using equations of motion :

• Acceleration must be uniform
• Motion of the object must be in a straight line

Answer 2

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

• A car is travelling along a straight road at 8.0m/s .

• It accelerates at 1.0m/s² for a distance of 18m .

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

• The final velocity of the car .

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

We have know that,

$\orange\bigstar\:\bf{\red{\overbrace{\underbrace{\purple{v^2\:-\:u^2\:=\:2\:a\:s\:}}}}}$

Where,

• $\bf\red{v}$ = Final velocity

• $\bf\red{u}$ = Initial velocity

• $\bf\red{a}$ = Acceleration

• $\bf\red{s}$ = Distance

✞︎ According to the question,

• $\bf\red{u}$ = 8.0 m/s

• $\bf\red{a}$ = 1.0 m/s²

• $\bf\red{s}$ = 18 m

➳ v² - 8² = 2 × 1 × 18

➳ v² = 64 + 36

➳ v² = 100

➳ v = √100

➳ v = 10 m/s

$\huge\red\therefore$ Car is traveling at "10 m/s" .