Question

A train accelerates from 20 km/h to 80 km/h in 4 minutes. How much distance does it cover in this period? Assume that the tracks are straight.

Answer 1

Answer:

The distance it covers in this period is 10/3 km

Step-by-step explanation:

Assuming the railway track are straight,

A train accelerated from 20 km/hr to 80km/hr in 4 minutes.

Given,

Time = 4 minutes = 4/60 hours = 1/15 hours.

Intital Velocity(u) = 20 km/hr

Final Velocity (v) = 80km/hr

We first find Acceleration (a)

Use first equation of motion,

v = u + at

⇒ a=v-u/t

⇒a = 80-20/1/15

⇒a = 60 × 15

⇒a = 900km/hr ²

Now, We find distance (s)

Use second equation of motion

s=ut+at²/2

⇒s =20(1/15)+900(1/15)(1/15)/2

⇒s =4/3+2

⇒s =10/3km

Therefore, The distance it covers in this period is 10/3 km