Question

a train moving with a speed of 180km/h comes to a stop at a constant acceleration in 15 min after covering a distance of 25 km. What is it's acceleration​

Answer 1

Step-by-step explanation:

we get two answers.

-640km/h^2 and 648 km/h^2.

HOPE THIS IS HELPFUL.

Answer 2

Given :

• Initial velocity of the train = 108 km/h

• Final velocity of the train = 0 m/s

• Time = 15 minutes

• Distance covered = 25 km

To find :

• Acceleration of the train

Solution :

Here, firstly we shall convert the velocity and distance covered from km/h and km respectively to m/s and m. Then by using the third equation of motion we will find the acceleration of the train.

→ Initial velocity = 108 km/h

→ To convert it from km/h into m/s multiply it by 5/18.

→ Initial velocity = 108 × 5/18 = 30 m/s

→ Distance = 25 km

→ 1 km = 1000 m

→ Distance = 25 × 1000 = 25000 m

Using third equation of motion :-

• v² - u² = 2as

where,

• u = Initial velocity
• v = Final velocity
• a = Acceleration
• s = distance/displacement

we have,

• u = 30 m/s
• v = 0 m/s
• s = 25000 m

Substituting the given values,

→ (0)² - (30)² = 2(a)(25000)

→ - 900 = 50,000 × a

→ - 900 ÷ 50,000 = a

→ 0.018 = a

Therefore, acceleration of the train = 0.018 m/s²