Question

A train accelerated from 36km/hr to 20 m/s in 4 minutes. How much distance does it cover in this period? Assume that the
tracks are straight?
3.6 km
2400 m
1600 m
1.8 km​

Answer 1

GiveN :

• Initial velocity (u) = 36 km/h = 10 m/s
• Final velocity (v) 20 m/s
• Time (t) = 4 mins = 240 s

To FinD :

• Distance travelled by train

SolutioN :

Using 1st equation of motion ,

➾ v = u + at

⇒20 = 10 + a * 240

⇒20 - 10 = 240a

⇒10 = 240a

⇒ a = 10/240

⇒a = 1/24

_________________________

Now, use 3rd equation of motion,

⇒v² - u² = 2*a*s

⇒ 20² - 10² = 2 * 1/24 * s

⇒ 400 - 100 = s/12

⇒ s = 300*12

⇒ s = 3600 m

⇒ s = 3.6 km

$\therefore$ Distance travelled by train is 3.6km.