Question

A bus decreases its speed from 80km per hour to 60km per hour in 5 seconds find the accleration of the bus

Answer 1

$\red{HEY\:BUDDY!!}$

HERE'S THE ANSWER..

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♠️ First we'll convert it speed to meter per second

▶️ 80 km / h to m / s

=> 80 × 5 / 18

=> 22.22 m / s

▶️ 60 km / h to m / s

=> 60 × 5 / 18

=> 16.66 m / s

♠️ We know

▶️ Acceleration = ( Final velocity - Initial velocity ) / time

⏺️ initial velocity ( u ) = 22.22 m / s

⏺️ Final velocity ( v ) = 16.66 m / s

⏺️time ( t ) = 5 second

=> Acceleration = ( v - u ) / t

=> Acceleration = ( 16.66 - 22.22 ) / 5

=> Acceleration = -5.56 / 5

=> $\boxed{ Acceleration\:= \: -1.11\: m/s^2}$

♠️ Here Acceleration is negative because velocity is decreasing . Or we can say it is Retarding .

HOPE HELPED..

$\red{JAI \:HIND..}$

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Answer 2

$\boxed{\underline{\bf{Given :}}}$

$\bf{\underline{initial\: velocity\: (u) = 80 km/h}}$

$= 80 \times \frac{5}{18} = 22.2$m/s

$\bf{\underline{final\: velocity \:(v) = 60 km/h}}$

$= 60 \times \frac{5}{18} = 16.6$m/s

$\bf{\underline{time\: (t) = 5 sec}}$

acceleration (a) = ?

We know that,

$a = \frac{(v - u)}{t} \\ \\ a = \frac{(16.6 - 22.2)}{5} \\ \\ a = \frac{ - 16.6}{5} \\ \\ a = - 1.1$

$\bf{\underline{Hence,\: the \:acceleration\: of \:the\: bus\:}}$ $\bf{\underline{will \:be \:-1.1 m/s}}$².