A mine car (mass mcar = 450 kg) rolls at a speed of vcar = 0.55 m/s on a horizontal track, as the drawing shows. An mcoal = 140 kg chunk of coal has a speed of vcoal = 0.73 m/s when it leaves the chute. Determine the speed of the car-coal system after the coal has come to rest in the car. (Assume the angle α = 26°.)

Respuesta :

Answer:

0.575 m/s

Explanation:

Data provided in the question:

Mass of the mine car, m₁ = 450 kg

Initial Velocity of the mine car, v₁ = 0.55 m/s

Mass of the coal chunk, m₂ = 140 kg

Initial velocity of the coal chunk, v₂ = 0.73 m/s

angle α = 26°

Now,

the horizontal component of the velocity of the coal chunk = v₂cos(α)

⇒ 0.73 × cos(26°)

⇒ 0.656

Now applying the concept of conservation of linear momentum in horizontal direction

we have

m₁v₁ + m₂v₂cos(α) = (m₁ + m₂)v

here v is the combined speed of the car-coal system

thus,

( 450 × 0.55 ) + ( 140 × 0.656) = (450 + 140) × v

or

247.5 + 91.84 = 590v

or

339.34 = 590v

or

⇒ v = 0.575 m/s

Answer:

The speed of the car-coal system after the coal has come to rest in the car is 0.37 m/s.

Explanation:

Given that,

Mass of car = 450 kg

Velocity of car = 0.55 m/s

Mass of coal = 140 kg

Velocity of coal = 0.73 m/s

Suppose the angle is horizontal angle .

[tex]\theta=26^{\circ}[/tex]

We need to calculate the speed of the car-coal system after the coal has come to rest in the car

Using conservation of momentum

[tex]m_{1}v_{1}\cos\theta=(m_{1}+m_{2})v_{x}[/tex]

Put the value into the formula

[tex]450\times0.55\cos26=(450+140)v_{x}[/tex]

[tex]v_{x}=\dfrac{450\times0.55\cos26}{450+140}[/tex]

[tex]v_{x}=0.37\ m/s[/tex]

Hence, The speed of the car-coal system after the coal has come to rest in the car is 0.37 m/s.

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