Question

10 ms.
11. A toy car initially moving with a uniform velocity
of 18 km h- comes to a stop in 2 s. Find the
retardation of the car in S.I. units.​

Answer 1

$\Huge{\underline{\tt{\green{Answer-}}}}$

Intial velocity = 18kmph = 5mps

final velocity = 0 ( as body stops)

time taken = 2 sec

acceleration = change in velocitiy/time

acceleration

= (final velocity- intial velocity)/time

a. = 0-5/2 = -2.5 mpss

negative acceleration is also called retardation

so retardation = 2.5mpss

Answer 2

AnSwEr :

${\red\bigstar\large\bold{\mathrm{\underline{\green{Given:}}}}}$

❥ Initial Velocity = 18 km/h = 5 m/s

❥ Final Velocity = Zero ( As it comes at rest )

❥ Time Taken = 2 seconds

${\red\bigstar\large\bold{\mathrm{\underline{\green{To\:Find:}}}}}$

❥ Retardation ( negative acceleration )

${\red\bigstar\large\bold{\mathrm{\underline{\green{Solution:}}}}}$

$\huge\bold{\sf{\underline{\orange{Formula\:Used:}}}}$

☯ v = u + at

Here , a is taken negative because it is case of retardation .

➡ 0 = 5 + (-a)2

➡ 0 = 5 - 2a

➡ 5 = 2a

➡ a = $\dfrac{5}{2}$

➡ a = 2.5

${\red\bigstar\large\bold{\mathrm{\underline{\green{Retardation\:=\:2.5\:{m}^{2}}}}}}$

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