Question

A bus devieases its speed 80 km/h to 60 km/h in
5 sec. find the acceleration of bus​

Answer 1

the first stanza of the novel in the test of the polynomial 4was 4the world

Answer 2

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✰Answer✰

♦️GiveN

• Speed decreases from 80 km/h to 60km/h
• Time taken is 5 sec.

♦️To FinD

• Accleration of the bus...?

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⭐As we can see the unit of speed in in kilometer/hr and the time taken is in seconds, Thus we need to convert tge units first for further Calculation.

✰Unit Conversion✰

➯Changing Speed in km/h to m/s,

$\large{ \tt{ \rightarrow \: 80 \: kmh {}^{ - 1} = 80 \times \frac{5}{18} ms {}^{ - 1} }} \\ \\ \large{ \tt{ \rightarrow \: 80 \: km {h}^{ - 1} = \cancel{ \frac{400}{18} m {s}^{ - 1} }}} \\ \\ \large{ \rightarrow \: \boxed{ \tt{ \purple{80 \: kmh {}^{ - 1} = \frac{200}{9} m {s}^{ - 1} }}}} \\ \\ \\ \large{ \tt{ \rightarrow \: 60 \: km {h}^{ - 1} = 60 \times \frac{5}{18} m {s}^{ - 1} }} \\ \\ \large{ \tt{ \rightarrow \: 60 \: km {h}^{ - 1} = \cancel{\frac{300}{18} m {s}^{ - 1} }} }\\ \\ \large{ \tt{ \rightarrow \: \boxed{ \purple{ \tt{60 \: km {h}^{ - 1} = \frac{150}{9} m {s}^{ - 1} }}}}}$

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♦️We multiply 5/18 because

$\large{ \tt{1km = 1000m}} \\ \\ \large{ \tt{1 hr = 3600s}} \\ \\ \large{ \tt{1 \: kmh {}^{ - 1} = \frac{1000}{3600} m {s}^{ - 1} = \frac{5}{18} \: m {s}^{ - 1} }}$

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✰Solution✰

➯We have,

• Initial velocity( u )= 200/9 m/s
• Final velocity(v) = 150/9 m/s
• Time taken(t) = 5 sec

➯By using 1st equation of motion,

$\large{ \star{ \boxed{ \tt{ \green{v = u + at}}}}}$

♦️Note: Symbols have their usual meanings.

➯By using the above equation,

$\large{ \tt{ \rightarrow \: \frac{150}{9} = \frac{200}{9} + \: a \times 5}} \\ \\ \large{ \tt{ \rightarrow \: \frac{ - 50}{9} = 5a}} \\ \\ \large{ \tt{ \rightarrow \: a = \frac{ \cancel{- 50} \: - 10}{9 \times \cancel{5}} }} \\ \\ \large{ \rightarrow \boxed{ \purple{ \tt{\: a = - 1 . \bar{1} \: m {s}^{ - 2} }}}}$

$\large{ \tt{ \star{ \orange{ \: accleration \: of \: the \: body = - 1 \bar{.1}}}}}$

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