Question

An automobile starts from rest form a station P and accelerated uniformly to
attain a speed of 48 kmph in 30 seconds. Hence, it covers distance
to
attain this speed.​

Answer 1

Answer:

200 m

Explanation:

Given:

Initial velocity (u) = 0 m/s  (as it started from rest)

Final velocity (v) = 48 km/h = 48 * 5/18 = 40/3 m/s

Time (t) = 30 seconds

To find:

Distance covered (s)

Method to find:

First, we need to find the acceleration (a).

v = u + at

⇒ 40/3 = 0 + 30a

⇒ a = (40/3)/30 = 4/9 m/s²

Now, we can find the distance.

v² = u² + 2as

⇒ (40/3)² = 0 + (2*4/9*s)

⇒ 1600/9 = (8/9)s

⇒ s = 1600/9 * 9/8

⇒ s = 200 m

(We could have also used the 2nd formula of motion, i.e, s = ut + 1/2at²)

Hence, the automobile covers 200 m to attain a velocity of 48 km/h.