Question

. A 12,000kg. railroad car is traveling at 2m/s when it strikes another 10,000 kg railroad car that is at rest. If the cars lock together, what is the final speed of the two railroad cars?

Answer 1

Given :

• Mass, m₁ = 12000 kg

• Velocity, u₁ = 2 m/s

• Mass, m₂ = 10000 kg

• Velocity, u₁ = 0 m/s

To find :

• Final speed, v

According to the question,

By using the formula of Conservation of momentum,

➞ m₁u₁ + m₂u₂ = ( m₁ + m₂)v

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

➞ 24000 + 0 = 22000v

➞ 24000 = 22000v

➞ 24000 ÷ 22000 = v

➞ 1.1 = v (approx)

So,the final speed of the two railroad cars is 1.1 m/s.

_____________________________

Momentum :-

• Momentum can be defined as the product of mass and velocity.

• SI unit of momentum is kg m/s.

• Momentum is vector quantity.

• Momentum is denoted by 'p'.

• Momentum = Mass × Velocity.

Answer 2

Answer:

Given :

Mass, m₁ = 12000 kg

Velocity, u₁ = 2 m/s

Mass, m₂ = 10000 kg

Velocity, u₁ = 0 m/s

To find :

Final speed, v

According to the question,

By using the formula of Conservation of momentum,

➞ m₁u₁ + m₂u₂ = ( m₁ + m₂)v

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

➞ 24000 + 0 = 22000v

➞ 24000 = 22000v

➞ 24000 ÷ 22000 = v

➞ 1.1 = v (approx)

So,the final speed of the two railroad cars is 1.1 m/s.

_____________________________

Momentum :-

Momentum can be defined as the product of mass and velocity.

SI unit of momentum is kg m/s.

Momentum is vector quantity.

Momentum is denoted by 'p'.

Momentum = Mass × Velocity.