Question

Please answer the below question on conservation of momentum (show full working)

Answer 1

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✤ Required Answer:

✒ GiveN:

• Mass of the moving railroad = 12000 kg
• Initially, it's velocity = 2 m/s
• Mass of railroad at rest = 10000 kg
• They collide and locked up

✒ To finD:

• Final speed of the system of railroad cars....?

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✤ How to solve?

Let's first know about law of conservation of momentum for colliding bodies:

• The law of conservation of momentum is commonly used when we need to find the velocities of objects that undergone some form of collision.
• The law of conservation of momentum states that the momentum of a system is conserved or remains constant as long as there are no external unbalanced forces acting on the system of bodies.

⚡It is given by,

• m1u1 + m2u2 = m1v1 + m2v2

Where,

• m1 and m2 are the masses of bodies.
• u1 and u2 are initial velocities
• And, v1 and V2 are final velocities$.$

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✤ Solution:

We have,

• m1 = 12000 kg
• m2 = 10000 kg
• u1 = 2 m/s
• u2 = 0 m/s (at rest)
• Final masses will be their sum

So, By using formula,

➝ m1u1 + m2u2 = (m1 + m2)v

➝ 12000 × 2 + 10000 × 0 = (12000 + 10000)v

➝ 24000 = 22000v

Flipping it,

➝ 22000v = 24000

➝ v = 24000 / 22000

➝ v = 12 / 11 m/s

➝ v = 1.1 m/s (approx.)

❒ Final velocity of the system = 1.1 m/s⚘

Hence, solved !!

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Answer 2

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❝ Solution: ❞

We have,

• m1 = 12000 kg

• m2 = 10000 kg

• u1 = 2 m/s

• u2 = 0 m/s (at rest)

So, By using formula,

➝ m1u1 + m2u2 = (m1 + m2)v

➝ 12000 × 2 + 10000 × 0 = (12000 + 10000)v

➝ 24000 = 22000v

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