Question

If a car at rest accelerates uniformly to a speed of 144 km/ hr in 20 seconds then it covers a distance of

Answer 1

Answer:

Explanation:

Correct Question,

If a car at rest accelerates uniformly to a speed of 144 km/hr in 20 seconds then find the distance covered by the car.

Solution,

Here, we have

Initial velocity, u = 0 m/s (As car is at rest)

Final velocity, v = 144 km/h = 144 × 5/18 = 40 m/s

Time taken, t = 20 seconds

To Find,

Distance covered, s = ?

At first we have to find acceleration,

According to the 1st equation of motion,

We know that,

v = u + at  

⇒ 40 = 0 + a × 20

⇒ 40 = 20a

⇒ 40/20 = a

⇒ a = 2 m/s²

Here, the acceleration is 2 m/s².

Now, the distance covered,

According to the 3rd equation of motion,

We know that,

v² - u² = 2as

⇒ (40)² - (0)² = 2 × 2 × s

⇒ 1600 = 4s

⇒ 1600/4 = s

⇒ s = 400 m.

Hence, the distance covered by car is 400 m.