Question

I applied brakes which caused retardation of 5 m/s^2 . Find the time taken to stop the scooty if its initial velocity was 40 m/s.​

Answer 1

Answer:

8 sec .

Explanation:

Given :

Initial velocity ( u ) = 40 m / sec

When break applied final velocity becomes zero i.e. v = 0 m / sec

Retardation ( - a ) = 5 m / sec²

We have to find time :

From first equation of motion we have :

v = u +  a t

Putting values here we get :

0 = 40 - 5 t

- 5 t = - 40

t = 8 sec .

Hence time taken is 8 sec to stop the scooty .

Answer 2

$\LARGE{\mathfrak{\underline{\blue{AnSwEr:-}}}}$

8 seconds

$\LARGE{\mathfrak{\underline{\red{Solution}}}}$

$\large{\mathrm{\green{Given:-}}}$

Inital velocity (u) = 40 m/s

Final velocity (v) = 0 m/s

Here, v = 0 because brakes are applied and scooty also stop after applying brakes.

- acceleration (- a) = 5 m/s²

$\large{\mathrm{\green{To \: find:-}}}$

Time interval

$\LARGE{\mathfrak{\green{S}}}{\mathfrak{o}}{\mathfrak{\orange{l}}}{\mathfrak{\red{u}}}{\mathfrak{\pink{t}}}{\mathfrak{\blue{i}}}{\mathfrak{\purple{o}}}{\mathfrak{\gray{n:-}}}$

We have formula :-

$\huge{\bf{\boxed{\boxed{v \: = \: u \: + \: at}}}}$

___________[Put Values]

⇒ 0 = 40 + -5(t)

⇒ 0 = 40 - 5t

⇒ -5t = -40

⇒ t = 40/5

⇒ t = 8 sec

$\large{\bigstar{\bf{\boxed{Time \: = \: 8sec}}}}$