Question

A car attains 54 km/h in 20s after it start from rest .find the acceleration of the car​

Answer 1

Solution :-

As given :-

▪️Initial speed of car = 0 m/s

▪️Final Speed of car = 54 km/h

= 54 × 5/18

= 15 m/s

▪️Time = 20 sec

As we know that

v = u + at

→ 15 = 0 + 20(a)

→ 15 = 20a

→ a = 15 ÷ 20

→ a = 3/4

→ a = 0.75 m/s²

So acceleration is 0.75 m/s²

Answer 2

Answer:

$\large{\underline{\boxed{\sf a = 0.75 \: ms^{-2}}}}$

Step-by-step explanation:

Initial velocity of car (u) = 0 m/s.

Final velocity of car (v) = 54 km/h

We need to convert km/h into m/s.

Final velocity = 54 km/h

= 54 * 5/18

= 15 m/s

Time taken (t) = 20 secs

We will use first equation of motion -

v = u + at

⇒ 15 = 0 + a * 20

⇒ 20a = 15

⇒ a = 15/20

⇒ a = 3/4

⇒ a = 0.75 m/s²

Hence, the acceleration of car is 0.75 m/s².