Question

A car starts from rest.It moves with the uniform acceleration. ln 10 seconds, It attains a speed of 90 km/hour on a straight road. Find its acceleration.

Answer 1

Answer:

2.5 m/s²

Explanation:

Car starts from rest

⇒ Initial velcity ( u ) = 0 m/s

Final velocity ( v ) = 90 Km/h = 90 × ( 5 / 18 ) = 5 × 5 = 25 m/s

Time ( t ) = 10 seconds

Let the acceleration of the car be 'a' m/s²

We know that

⇒ a = ( v - u ) / t

⇒ a = ( 25 - 0 ) / 10

⇒ a = 25 / 10

⇒ a = 2.5

Therefore the acceleration if the car is 2.5 m/s²

Answer 2

$\large{\underline{\underline{\mathfrak{Answer :}}}}$

• Acceleration of car is 2.5 m/s²

$\rule{200}{0.5}$

$\underline{\underline{\mathfrak{Step-By-Step-Explanation :}}}$

Given :

• Initial velocity (u) = 0 m/s
• Final velocity (v) = 90 km/h = 25 m/s
• Time (t) = 10s

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To Find :

• Acceleration of Car

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Solution :

We have formula for acceleration :

$\large{\boxed{\boxed{\sf{a \: = \: \dfrac{v \: - \: u}{t}}}}} \\ \\ \implies {\sf{a \: = \: \dfrac{25 \: - \: 0}{10}}} \\ \\ \implies {\sf{a \: = \: \dfrac{25}{10}}} \\ \\ \implies{\sf{a \: = \: 2.5}} \\ \\ \underline{\sf{\therefore \: Acceleration \: of \: car \: is \: 2.5 \: ms^{-2}}}$

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$\large{\underline{\underline{\mathfrak{Additional \: Information \: :}}}}$

• Acceleration is defined as rate of change of velocity.

• It is denoted by small a.

• It is a vector quantity.

• It's SI unit is m/s²

• a = v-u/t