Question

2. A car starting from rest and moving with uniform ace
-eleration attains a speed of 60km/h in 20 Minutes find its
acceleration in km/h²​

Answer 1

Given

A car starting from rest and moving with uniform acceleration attains a speed of 60 km/h in 20 minutes

To Find

Acceleration (km/h²)

Solution

We know that

Equation of motion

$\sf \longrightarrow v=u+at$

Here

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

According to the question

We are asked to find acceleration

Hence

We must find "a"

Therefore

$\sf \longrightarrow a=\dfrac{v-u}{t}$

Given that

A car starting from rest and moving with uniform acceleration attains a speed of 60 km/h in 20 minutes

Hence

• u = 0 [starts from rest]
• v = 60 km/h
• t = 20 min = 0.333 hour

Substituting the values

We get

$\sf \longrightarrow a=\dfrac{60-0}{0.333} \ km/h^{2}$

$\sf \longrightarrow a=\dfrac{60}{0.333} \ km/h^{2}$

$\sf \longrightarrow a=180.18 \ km/h^{2}$

Therefore

$\sf \longrightarrow a \approx 180 \ km/h^{2}$

Hence

Acceleration = 180 km/h²

Answer 2

Answer:

Given :-

• A car starting from rest and moving with uniform acceleration attains a speed of 60 km/h in 20 m .

To Find :-

• What is the acceleration in km/h²

Formula Used :-

To find acceleration we have to use SUVAT equation,

$\leadsto\boxed{\bold{\large{\mathscr{a\: =\: \dfrac{v - u}{t}}}}}$

where,

• a = Acceleration
• v = Final velocity of the object
• u = Initial velocity of the object
• t = Time

Solution :-

Given :

• Final velocity = 60 km/h
• Initial velocity = 0
• Time = 20m = $\dfrac{20}{60}$ = 0.333 hr

According to the question by using the formula we get,

⇒ a = $\dfrac{60 - 0}{0.333}$

⇒ a = $\dfrac{60}{0.333}$

➥ a = 180.18 ≈ 180 km/h²

∴ The acceleration of a car is 180 km/h².

________________________________