Question

The car accelerates uniformly from 18 km per hour in 5S. calculate a) the acceleration b)the distance covered by the car in that time.​

Answer 1

Explanation:

Solution,

Here, We have initial and final velocity and time taken.

Initial velocity, u is given as 18 km/h, So we have to convert it into m/s,

For that we have to multiply it with 5/18,

So, 18 × 5/18 = 5 m/s.

Similarly, the final velocity is given as 36 km/s.

So, 36 × 5/18 = 10 m/s.

Now, time taken is also given as 5 seconds,

Here, we have to find,

Acceleration and Distance covered.

According to the first equation of motion,

We know that,

v = u + at

So, putting all the values, we get

⇒ v = u + at

⇒ 10 = 5 + a × 5

⇒ 10 - 5 = 5a

⇒ 5 = 5a

⇒ 5/5 = a

⇒ a = 1 m/s².

Hence, the acceleration of the car is 1 m/s².

Now, we have to find the distance covered, s

According to the 3rd equation of motion,

we know that,

v² - u² = 2as

So, putting all the values again, we get

⇒ v² - u² = 2as

⇒ (10)² - (5)² = 2 × 1 × s

⇒ 100 - 25 = 2s

⇒ 75 = 2s

⇒ 75/2 = s

⇒ s = 37.5 m.

Hence, the distance covered by car is 37.5 m.