Question

A can increases it speed from 20km/h to 50 km/h in 10
Seconds,
what is the acceleration​

Answer 1

Explanation:

is given that the car increases its speed from 20 km per hour to 50 km per minute in 10 seconds.

It means that the initial velocity of the car is 20 km / hr.

And, the final velocity of the car is 50 km / hr

Since km can be written as 1000m and 1 hour can be written as ( 60 x 60 ) seconds.

Thus,

Initial velocity of the car = 20 km / hr = 20 x 1000 m / 3600 sec = 20000 m / 3600 s = 200 m / 36 s = 100 m / 18 s = 50 m / 9 s

And,

Final velocity of the car = 50 km / hr = 50 x 1000 m / 3600 s = 50000 m / 3600 s = 500 m / 36 s = 250 m / 18 s = 125 m / 9 s

From the properties of acceleration :

Acceleration = ( change in velocity ) / ( time taken for the change in velocities )

Therefore,

Acceleration = [ Final velocity - initial velocity ] / time taken

= > Acceleration = [ 125 / 9 - 50 / 9 ] / 10 x m / s²

= > Acceleration = 75 / 9 x 1 / 10 x m / s²

= > Acceleration = 75 / 90 x m / s²

= > Acceleration ≈ 0.83 m / s²

Hence,

Acceleration is 0.83 m / s² .

\:

Answer 2

$\boxed{\bf{\green{Find \longrightarrow }}}$

Acceleration??

$\boxed{\bf{\red{Given \longrightarrow }}}$

• Intial speed [u] = 20km/h
• Final speed [v] = 50km/h
• Time = 10 sec

$\boxed{\bf{\blue{Formula \ used \longrightarrow }}}$

• $\bf{a=\dfrac{v-u}{t}}$

$\boxed{\bf{\orange{SoLution \longrightarrow }}}$

$\sf{u=20km =20\times \dfrac{5}{18} = 5.55m/s }$

$\sf{v=50km/h = 50\times \dfrac{5}{18} = 13.88m/s}$

Put the values of u, v and t in above formula we get,

$\sf{\implies a= \dfrac{13.88-5.55}{10} = \dfrac{8.33}{10} = 0.833m/s^2 }$

$\underline{\bf {\pink{ \therefore Acceleration = 0.833m/s^2\bigstar }}}$

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