Question

• moderator
• brainly stars
pls answer this

$\bold{Q/- Shatabdi \: express \: starts \: from }\\ \bold{rest \: and \: attains \: a \: velocity \: of } \\ \bold{ \: 108km/h \: in \: 2min. \: If \: acceleration} \\ \bold{\: is \: uniform \: fild \: acceleration \: } \\ \bold{ \: and \: displacement \: of \: the \: train.}$
​

Answer 1

EXPLANATION:-

We know:-

u=0

v=108 km/hr=108×5/18

v=30 m/s

2 min=120 second

Let's apply 1st equation here

v=u+at

30=0+a×120

30=120a

a=30/120

a=3/12

a=0.25 m/s²

So acceleration of the car is 0.25 m/s²

Now let's calculate the displacement using 2nd equation:-

$\sf\;s=ut+\frac{1}{2}at^2\\\\s=\frac{1}{2}at^2 \;\;\;\;\; (Since\;u\;is\;0)\\\\s=\frac{1}{2}0.25\times(120)^2\\\\s=\frac{1}{2}0.25\times14400\\\\s=7200\times0.25\\\\s=1800\;m$

Hence the displacement is 1800 meters or 1.8 km

Answer 2

Answer:

Acceleration of the train is 0.25m/s²

Displacement of the train is 1.8km

Explanation:

According to the Question

It is given that ,

•Initial velocity ,u = 0m/s

•Final velocity ,v = 108×5/18 = 30m/s

•Time taken ,t = 2min = 2×60 = 120s

we have to calculate the uniform acceleration of the train and displacement of the train .

Firstly we calculate the uniform acceleration of the train .

Using Kinematics Equation

a = v-u/t

Substitute the value we get

$\sf{➾ a \:=\: 30-0/120}$

$\sf{➾ a \:= \:30/120}$

$\sf{➾ a\: =\: 1/4 }$

$\sf{➾ a\: =\: 0.25m/s²}$

Hence, the acceleration of the train is 0.25m/s²

Now, calculating the displacement of the train .

Again using Kinematics Equation

v² = u² + 2as

Puttng all the values we get

$\sf{➾ 30² \:=\: 0² + 2×0.25 × s}$

$\sf{➾ 900\: =\: 0 + 0.50 × s}$

$\sf{➾ 900\: = \:0.50×s}$

$\sf{➾ s \:= \:900/0.50}$

$\sf{➾ s\: = \:1800m}$

$\sf{➾ s\: = \:1.8km}$

Hence, the displacement of the train is 1.8 kilometres.

_____________________________________