Question

The velocity of a train increases uniformly from 20 km-h-1 t o60 km-h-1 in 0.2 h the distance travelled by the train during this period is
A) 0.2 km
B) 0.4 km
C) 0.6 km
D) 1.2 km

Answer 1

Answer:

8 km

Explanation:

As per the provided information in the given question, we have :

• Initial velocity (u) = 20 km/h
• Final velocity (v) = 60 km/h
• Time taken (t) = 0.2 h

We are asked to calculate the distance travelled by the train during this period.

Let us find out the acceleration first.

➝ v = u + at

• v denotes final velocity
• u denotes initial velocity
• a denotes acceleration
• t denotes time

➝ 60 = 20 + 0.2a

➝ 60 – 20 = 0.2a

➝ 40 = 0.2a

➝ 40 ÷ 0.2 = a

➝ 200 km/h² = a

Now, by using the third equation of motion,

➝ v² – u² = 2as

• v denotes final velocity
• u denotes initial velocity
• a denotes acceleration
• s denotes distance

➝ (60)² – (20)² = 2 × 200 × s

➝ 3600 – 400 = 400s

➝ 3200 = 400s

➝ 3200 ÷ 400 = s

➝ 8 km = s

None of the options is correct. The distance travelled by the train during this period is 8 km.