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Free_Kalibri [48]
2 years ago
13

An empty 2,500 kg train car is headed northbound at a velocity of 5 m/s. Ahead of the first car, an empty 1,500 kg car is headed

northbound on the same track at 1 m/s. The faster train bumps into the slower one, and they combine into one train. What is the velocity of the two-car train? 1 m/s 3 m/s 3. 5 m/s 5 m/s.
Physics
1 answer:
Nimfa-mama [501]2 years ago
7 0

The velocity of the two-car train is 3.5 m/s.

To solve the problem above, we use the law of conservation of momentum

Law of conservation of momentum: States that, for a closed system, the total momentum before collision is equal to the total momentum after collision.

⇒ Formula:

mu+m'u' = V(m+m')..................... Equation 1

⇒ Where:

  • m = mass of the faster train
  • m' = mass of the slower train
  • u = initial velocity of the faster train
  • u' = initial velocity of the slower train
  • V = common velocity of the two trains

⇒ make V the subject of the equation

  • V = (mu+m'u')/(m+m')....................... Equation 2

From the question,

⇒ Given:

  • m = 2500 kg
  • m' = 1500 kg
  • u = 5 m/s
  • u' = 1 m/s

⇒ Substitute these values into equation 2

  • V = [(2500×5)+(1500×1)]/(2500+1500)
  • V = [12500+1500]/(4000)
  • V = 14000/4000
  • V = 3.5 m/s.

Hence, The velocity of the two-car train is 3.5 m/s

Learn more about the law of conservation of momentum: brainly.com/question/9408577

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A circular window of 30 cm diameter in a submarine can withstand a maximum force of 5.20 × 105 N. The maximum depth in a lake to
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Answer: Option (b) is the correct answer.

Explanation:

The given data is as follows.

         F = 5.20 \times 10^{5} N

         g = 9.8 m/s

         radius = \frac{diameter}{2}

                    = \frac{30 cm}{2} = 15 cm = 0.15 m   (as 1 m = 100 cm)

Formula to calculate depth is as follows.

        F = \rho \times g \times h \times A

or,      h = \frac{F}{\rho \times g \times A}        

       h = \frac{5.2 \times 10^{5}}{1000 \times 9.8 \times (3.1416 \times (0.15 m^{2})}

           = 751 m

Thus, we can conclude that the maximum depth in a lake to which the submarine can go without damaging the window is closest 750 m.

3 0
4 years ago
f a single circular loop of wire carries a current of 45 A and produces a magnetic field at its center with a magnitude of 1.50
Lelu [443]

Answer:

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Explanation:

Given :

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Consider R be the radius of the circular wire.

The magnetic field at the center of the current carrying circular wire is determine by the relation:

B=\frac{N\mu_{0} I}{2R}

Here μ₀ is vacuum permeability constant and its value is 4π x 10⁻⁷ Tm/A.

Substitute the suitable values in the above equation.

1.50\times10^{-4} =\frac{4\pi \times10^{-7}\times45 }{2R}

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Explanation:

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final angular velocity of the  ice skater, ω₂ = 10.0 rev/s

During this process we assume that angular momentum is conserved;

I₁ω₁ = I₂ω₂

Where;

I₁ is the initial moment of inertia

I₂ is the final moment of inertia

I_2 = \frac{I_1 \omega_1}{\omega_2} = \frac{I_1*2.5}{10} \\\\I_2 = 0.25I_1 = \frac{1}{4}I_1

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If an object is dropped from a tall building and hits the ground 3.0 s later, how tall is the building?
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