Question

what is the acceleration of a car while started from rest and acquired a velocity of 40m/s in 8 seconds?
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Answer 1

Given :

• Initial velocity (u) = 0 m/s (as it is starts from rest)
• Final velocity (v) = 40 m/s
• Time (t) = 8 seconds

To find :

• Acceleration (a)

According to the question,

By using Newtons first equation of motion,

→ v = u + at

Where,

• v = Final velocity
• u = Initial velocity
• a = Acceleration
• t = Time

→ Substituting the values,

→ 40 = 0 + a × 8

→ 40 - 0 = 8a

→ 40 = 8a

→ 40 ÷ 8 = a

→ 5 = a

So,the acceleration of the car is 5 m/s².

_________________________

More formulas :

Newton's first equation of motion :

• v = u + at

Newton's second equation of motion :

• s = ut + ½ at²

Newton's third equation of motion :

• v² = u² + 2as

★ Acceleration :

The rate of change of velocity per unit time is known as acceleration.

• SI unit of acceleration is m/s²

• Acceleration is vector quantity.

Answer 2

Answer:

✯ Given :-

• A car while stated from rest and acquired a velocity of 40 m/s in 8 secs.

✯ To Find :-

• What is the acceleration of a car.

✯ Formula Used :-

Newton's First law of motion :

$\boxed{\bold{\large{✮\: v\: =\: u\: +\: at\: ✮}}}$

✯Solution :-

⋆ Given :

• Final velocity (v) = 40 m/s
• Initial velocity (u) = 0 m/s
• Time (t) = 8 secs

➣ According to the question by using the formula we get,

⇒ v = u + at

By putting the values we get,

⇒ 40 = 0 + a × 8

⇒ 40 = 8a

⇒ - 8a = - 40

⇒ a = $\dfrac{- 40}{- 8}$

➠ a = 5 m/s²

$\therefore$ The acceleration of a car is 5 m/s² .