Question

A car moves with a speed of 100m/s and comes to rest by applying brakes in 10sec.Find the retardation.​

Answer 1

Answer:

10m/s²

Explanation:

initial velocity = u = 0m/s

Speed = velocity = v = 100m/s

time = t = 10s

acceleration = a = v-u

t

so 100-0

10

= 100/10 = 10m/s²

HOPE THIS HELPS

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Answer 2

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

• Retardation is -10 m/s²

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

GiveN :

• A car moving with a speed of 100 m/s
• It comes to rest after applying breaks, in 10 seconds.

To FinD :

• Retardation (a)

SolutioN :

• We are given that a car is moving with a speed of 100 m/s. So, it means initial velocity is 100 m/s.

• Breaks are applied to the car and it comes to rest. So, it means final velocity is 0 m/s.

• Time interval to come to rest is given as 10 seconds.

So, with this data we come to know that :

• Initial velocity (u) = 100 m/s
• Final velocity (v) = 0 m/s
• Time interval (t) = 10 seconds

For calculating acceleration we've to use first equation of motion.

$\longrightarrow \sf{v \: = \: u \: + \: at} \\ \\ \longrightarrow \sf{0 \: = \: 100 \: + \: 10 \: \times \: a} \\ \\ \longrightarrow \sf{0 \: - \: 100 \: = \: 10a} \\ \\ \longrightarrow \sf{10a \: = \: -100} \\ \\ \longrightarrow \sf{a \: = \: \dfrac{-100}{10}} \\ \\ \longrightarrow \sf{a \: = \: -10} \\ \\ \underline{\boxed{\sf{a \: = \: - 10 \: ms^{-2}}}}$

Acceleration is 10 m/s² , negative sign shows that acceleration is applied in opposite direction of motion (which is also known as retardation) .