Question

2. A bus decreases its speed from
80 km/h to 60 km/ hr in 5 s.
Find the acceleration of the bus.​

Answer 1

Answer:

initial speed (u) : 80 km/h =22.2 m/s

final speed (v) : 60 km/h = 16.6 m/s

time taken (t): 5 s

acceleration (a) : ?

acceleration of the bus :

$\frac{change \: in \: speed \: or \: velocity}{time} \\ \frac{v - u}{t} \\ = \frac{ 16.6 - 22.2}{5} \\ = \frac{ - 5.6}{5} \\ = - 1.12 \: m {s}^{ - 2}$

so, the negative sign denote that the bus is decelerating at the rate of,

1.12 m/s².

Answer 2

$\large{\mathfrak{\underline{\underline{Answer:-}}}}$

1m/s²

${\mathfrak{\underline{\underline{Step-By-Step-Explanation:-}}}}$

Question-

A bus decreases its speed from 80km/h to 60km/h in 5s .Calculate its acceleration.

Solution-

Time = 5sec

Convert Speed into m/s from km/h

u(Initial Speed) = 80 km/h

⟹ u = 80 * 5/18

⟹ u = 22.22

⟹ u = 22m/s

$\large{\star{\boxed{\boxed{u \: = \: 22m/s}}}}$

v(Final Speed) = 60 km/h

⟹ v = 60 * 5/18

⟹ v = 16.66

⟹ v = 17 m/s

$\large{\star{\boxed{\boxed{v \: = \: 17m/s}}}}$

Use Formula :-

$\huge{\bigstar{\boxed{\boxed{a \: = \: {\frac{v \: - u}{t}}}}}}$

_________________[Put Values]

a = 17 - 22 / 5

⟹ a = - 5/5

⟹ a = 1

⇒ a = 1m/s²

$\huge{\star{\boxed{\boxed{a \: = \: 1m/s^{2}}}}}$

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Retardation -

Negate sign of acceleration means that Acceleration is in opposite direction.

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