Question

a car which is moving with velocity of 60km/he comes to rest in 5sec calculate its acceleration​

Answer 1

Given:

Initial velocity of car,u= 60 km/h

Final velocity of car,v= 0 km/h

Time taken by car,t= 5 s

To Find:

Acceleration of car

Solution:

We know that,  

• According to first equation of motion for constant acceleration,

$\pink{\underline{\boxed{\bf{v=u+at}}}}$

where,

v is final velocity

u is initial velocity

a is acceleration

t is time taken

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It is given that,

$\longrightarrow\rm{u=60\ km/h=60\times\dfrac{5}{18}\ m/s=\dfrac{50}{3}\ m/s}$

$\longrightarrow\rm{v=0\ km/h=0\times\dfrac{5}{18}\ m/s=0\ m/s}$

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Let the acceleration of car be a

So, on applying first equation of motion on car, we get

$\longrightarrow\rm{v=u+at}$

$\longrightarrow\rm{0=\dfrac{50}{3} +a(5)}$

$\longrightarrow\rm{-\dfrac{50}{3}=5a}$

$\longrightarrow\rm{5a=-\dfrac{50}{3}}$

$\longrightarrow\rm{a=-\dfrac{10}{3}}$

$\longrightarrow\rm\green{a=-3.33\ m/s^{2}}$

Hence, the acceleration of car is -3.33 m/s².

Answer 2

Answer -

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Given

$\implies$u = 60 km/hr

$\implies$v = 0 ( because car comes to rest )

$\implies$t = 5sec = 0.08 hr

where

$\longrightarrow$u is initial velocity

$\longrightarrow$v is final velocity

$\longrightarrow$t is time

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To find -

Acceleration $\longrightarrow$ a

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Formula used -

$\longrightarrow$$\boxed{a = \frac{v - u}{t}}$

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Solution -

$a = \frac{0 - 60}{0.08}$

$\longrightarrow$$\frac{ - 60}{0.08}$

$\implies$750km/hr

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ADDITIONAL INFORMATION :-

Acceleration is the rate of change of velocity with respect to time.

5/18 km/hr = m/s

$\implies$v = u + at

$\implies$v² = u² + 2as

$\implies$s = ut + ½at²

$\implies$Snth = u + (2n - 1)a/2

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Thanks