Question

A car starts motion from rest with speed of 20m/s calculate acceleration after 4 seconds.​

Answer 1

$\bigstar$ Answer $\bigstar$

$\checkmark$ Given:

A car starts motion from rest with speed of 20 m/s

$\checkmark$ To Find:

Acceleration after 4 seconds.​

$\checkmark$ Solution:

We know that,

$\star$ Equation of Motion

$\red{\implies \ \boxed{\rm v=u+at}}$

Here,

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

Given that,

A car starts motion from rest with speed of 20 m/s

According to the Question,

We are asked to find Acceleration (a)

Therefore,

• u = 0 m/s (starts from rest)
• v = 20 m/s
• t = 4 seconds

Hence,

Substituting the above values,

We get,

$\green{\rm \implies 20=0+a(4)}$

$\blue{\rm \implies 20=a(4)}$

$\greeb{\rm \implies 4a=20}$

$\red{\rm \implies a=\dfrac{20}{4} \ m/s^{2}}$

$\orange{\rm \implies a=5 \ m/s^{2}}$

Hence,

Acceleration after 4 seconds is 5 m/s²

Therefore,

$\checkmark$ Acceleration (a) = 5 m/s²

Answer 2

✰ Given -

• Initial Velocity (u) = 0 m/s
• Final Velocity (v) = 20 m/s
• Time = 4 sec

✰ To Find -

• Acceleration = ?

✰Solution -

We know Formula for 1st Eqn Motion,

$✓ \: v = u + at$

Here,

• V = Final Velocity
• U = Initial Velocity
• A = Acceleration
• T = time

Placing Values,

$⟶20 = 0 + a \times (4)$

$⟶20 = 4a$

$⟶4a = 20$

$⟶a = \frac{\cancel{20}}{\cancel{4}}$

$⟶a = 5 {m/s}^{2}$

⛬ Acceleration produced is 5 m/s²