Question

A bus travelling at 15km/h, comes to rest with uniform retardation in 30 seconds. Calculate the retardation of the bus.​

Answer 1

Answer:

Answer

Initial velocity, u=18 km/h

u=18×

3600

1000

=

3600

18000

m/s=5m/s

Final velocity, v=0 m/s

Time, t=2.5 sec

Acceleration, a=?

Using, v=u+at

a=

t

v−u

=

2.5

0.5

=−2m/s

2

So, retardation is 2m/s

2

..

Answer 2

$\sf\purple{ \clubs \:Given : }$

A bus travelling at 15km/h, comes to rest with uniform retardation in 30 seconds.

$\sf\purple{ \clubs \:To \: find: }$

Retardation of the bus .

$\sf\purple{ \clubs \:Solution : }$

Initial velocity (u) = 15 km/h

Initial velocity (u) in m/s = 4.17 m/s

Final velocity (v) = 0 ( At rest )

Time (t) = 30 s

Retardation (a) = ?

Formula used :

v = u + at

$\longmapsto \tt 0 = 4.17 + a(30) \\ \longmapsto\tt4.17 + 30a = 0 \: \: \: \\ \longmapsto\tt30a = - 4.17 \: \: \: \: \: \: \: \\ \longmapsto \tt \: a = \frac{ - 4.17}{30} \: \: \: \: \: \: \: \: \: \\ \: \: \longmapsto \tt \: a = - 0.139 \: m {s}^{ - 2}$

$\purple{{ \underline{ \boxed{ \sf \: Retardation \: of \: the \: bus = 0.139 \: m {s}^{ - 2} }}}}$