Question

Q3 A car starts from rest. It moves with uniform acceleration. In 20 seconds it

attains a speed of 126 km/h on a straight road. Find it’s acceleration.​

Answer 1

Answer:

u=0

v=126 km/hr = 126×1000÷3600=35m/ sec

t=20 s

a=?

a=v-u÷ time

= 35-0 ÷ 20

=1.75 m / s ²

Explanation:

here the initial velocity is zero since it is starting from rest and finial velocity is 126 km/ hr , since final velocity is in km / hr we will change it to m/ sec !

here the question is asking us to find the acceleration so the formula for acceleration is final velocity subtracted by intial velocity divided by time !

I hope it help you ty

Answer 2

Explanation:

☆To find:

•Acceleration of the car

☆Given:

•The car starts from rest.

•In 20 sec it attains a spead of 126 km/hr

☆Formula:

•v=u+at

☆ Solution:

•Initial velocity =0

•Final velocity =126 km /hr

$= \frac{126 \times 5}{18} = 35m \: per \: sec$

•Time = 20 sec

•Now,the acceleration

•Using of equation of motion

$35 = 0 + a \times 20 \\ = > 35 = 20a \\ = > a = \frac{35}{20} = 1.75m \: per \: sec ^{2}$

☆Hence:

•Acceleration is 1.75 m/s²

☆Note:

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Equation of motion:

• v=u+at
• s=ut +(1/2)at²
• 2as=v²-u²

Here v=final velocity, u= Initial velocity, a=Acceleration, t=time and s= distance

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hope it helps.....