Question

A car is moving at 60m/s, what was the initial speed if it accelerate at 2.5m/s2 for 12 seconds?

Answer 1

$\huge\sf\pink{Answer}$

☞ Initial Velocity of the body is 30 m/s

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$\huge\sf\blue{Given}$

✭ Final Velocity = 60 m/s

✭ Acceleration = 2.5 m/s²

✭ Time = 12 sec

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$\huge\sf\gray{To \:Find}$

◈ Initial Speed of the body?

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$\huge\sf\purple{Steps}$

$\large\underline{\underline{\sf Acceleration}}$

☆ Acceleration is equal to the change in the velocity of a body per unit time

☆ SI unit of acceleration is m/s²

☆ Acceleration = v-u/t

☆ Acceleration is a vector qualitiy,i.e it has both magnitude and direction

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So here as we are given the values of v,a & t we shall use the first equation of motion to find the value of a, that is,

$\underline{\boxed{\sf v = u+at}}$

• v is the final velocity
• u is initial velocity
• a is acceleration
• t is time taken

Substituting the given values,

➝ $\sf v = u+at$

➝ $\sf 60 = u+2.5 \times 12$

➝ $\sf 60 = u+30$

➝ $\sf 60-30 = u$

➝ $\sf \orange{Initial \ Velocity = 30 \ m/s}$

☯ $\underline{\sf Know \ More}$

⪼ s = ut + ½ at²

⪼ v = u + at

⪼ v² = u² + 2as

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Answer 2

Given :

• Final velocity (v) = 60 m/s
• Acceleration (a) = 2.5 m/s²
• Time (t) = 12 seconds

To find :

• Initial velocity (u)

According to the question,

$\star \boxed{ \sf \purple{v = u + at}}$

Where,

• v stands for Final velocity
• u stands for Initial velocity
• a stands for Acceleration
• t stands for Time

Now according to the formula we will put the values,

$\sf{ \: \: : \implies60 = u + 2.5 \times 12 }$

$\sf{ \: \: : \implies60 = u + 30}$

$\sf{ \: \: : \implies60 - 30 = u }$

$\sf{ \: \: : \implies 30 \: {ms}^{ - 1} = u } \orange\bigstar$

.°. The initial velocity is 30 m/s....