Question

A train accelerates uniformly from 30 kmh-1

to 60 kmh-1

in 30 seconds. Calculate

(i) the acceleration and
(ii) the distance covered

Thank you so much in advance

Answer 1

Explanation:

Given :

Initial velocity = 18km/hr

Final velocity = 36km/hr

Time interval = 5s

To Find :

Acceleration of car and distance covered.

Solution :

❖ Acceleration is defined as the rate of change of velocity..

It is a vector quantity having both magnitude as well as direction.

It can be positive, negative or zero.

SI unit : m/s²

Dimension formula : [L¹T‾²]

Formula : a = (v - u) / t

» u = 18 km/hr = 5 m/s

» v = 36 km/hr = 10 m/s

By substituting the given values;

➙ a = (10 - 5) / 5

➙ a = 5/5

➙ a = 1 m/s²

❒ Distance travelled by car :

Applying 3rd equation of kinematics;

➠ v² - u² = 2as

➠ 10² - 5² = 2(1)s

➠ 100 - 25 = 2s

➠ 2s = 75

➠ s = 75/2

➠ Answer - s = 37.5 m