Question

a car initially at rest, picks up a velocity of 72 kmph over a distance 25 m the acceleration ofa car is ?​

Answer 1

$\huge \red{ \tt Solution:-}$

$\purple{ \sf Given :-}$

• $\green{\sf Initial \: Velocity \: (u) = 0 \: m/s}$
• $\green{\sf Final \: Velocity \: (v) = 72 \: km/hr = 20 \: m/s}$
• $\green{\sf Distance \: Covered \: (s) = 25 \: m}$

$\huge \orange{\bf Calculating \: Acceleration}$

$\blue{\tt Formula \: Used :-}$

• $\gray{ \underline {\boxed{ { \tt{ v}^{2} - {u}^{2} = 2as }}}}$

$\implies \pink{( \sf {20)}^{2} - ( {0)}^{2} = 2 \times a \times 25 }$

$\implies \pink{ \sf 400 - 0 = 50a}$

$\implies \pink{ \sf 50a = 400}$

$\implies \pink{ \sf a = \cancel{\dfrac{400}{50}} }$

$\implies \pink{ \sf a = 8}$

${\green{ \underbrace{\boxed{\underline{\underline{\purple{ \tt \therefore The \: acceleration \: is \: 8 \: m/s^{2} }}}}}}}$

Answer 2

Answer :

›»› The Acceleration of a car = 8 m/s²

Given :

• Initial velocity of car = 0 m/s
• Final velocity of car = 72 km/hr
• Distance travelled by car = 25 m

To Find :

• Acceleration of car = ?

Required Solution :

Here in this question we have to find the Acceleration of car. So, firstly we have to convert the Final velocity of car km/hr to m/s, after that we will find Acceleration of car on the on the basis of conditions given above.

→ Final velocity = 72 km/hr

→ Final velocity = 72 × 5/18

→ Final velocity = 4 × 5

→ Final velocity = 20 m/s

Now, we have Initial velocity, Final velocity and Distance travelled by car.

• Initial velocity of car = 0 m/s
• Final velocity of car = 20 m/s
• Distance travelled by car = 25 m

And we need to find Acceleration of car.

From third equation of motion

$\tt{:\implies {v}^{2} = {u}^{2} + 2as}$

$\tt{:\implies {20}^{2} = {0}^{2} + 2 \times a \times 25}$

$\tt{:\implies 400 = 0 + 2 \times a \times 25}$

$\tt{:\implies 400 = 0 + 2a \times 25}$

$\tt{:\implies 400 = 0 + 50a}$

$\tt{:\implies 400 = 50a}$

$\tt{:\implies \dfrac{40\cancel{0}}{5\cancel{0}} = a}$

$\tt{:\implies \cancel{\dfrac{40}{5}} = a}$

$\tt{:\implies 8 = a}$

$\bf{:\implies \underline{\:\: \underline {\red{\: a = 8 \: m/s^2\:}}\:}}$

║Hence, the Acceleration of car is 8 m/s².║

$\:$

Additional Information :

★ First equation of motion :

⪼ v = u + at

Where,

• v is the Final velocity in m/s.
• u is the Initial velocity in m/s.
• a is the Acceleration in m/s².
• t is the Time taken in second.

★ Second equation of motion :

⪼ s = ut + ½ at²

Where,

• s is the Distance travelled in m.
• u is the Initial velocity in m/s.
• a is the Acceleration in m/s².

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