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Anna [14]
3 years ago
6

A 30 kg mass and a 20 kg mass are joined by a light rigid rod and this system is free to rotate in the plane of the page about a

xis through A and perpendicular to the page. The 30 kg mass is 0.2 m from A and the 20-kg mass is 0.4 m from A. Treating the masses as point masses and assuming the system rotates at 5 rad/s about A, what is the total kinetic energy?
Physics
2 answers:
stepan [7]3 years ago
3 0

55 J

Explanation:

Kinetic energy is given as: 0.5MV^2 where M is the mass and V is the speed of rotation. Since the masses are point masses, we calculate the point mass for each mass.

M1 = 30*0.2^2 = 1.2kgm^2

M2 = 20*0.4^2 = 3.2kgm^2

V = 5 rad/s

Calculating using the formula above, we obtain :

0.5(1.2+3.2)5^2 =0.5*4.4*25 = 55 J

sertanlavr [38]3 years ago
3 0

Answer:

  K = 55 J

Explanation:

Kinetic energy is a scalar therefore it is an additive quantity

       K = ½ I₁ w₁² + ½ I₂ w₂²

The moment of inertia of a particular is

      I = m r²

      I₁ = 30 0.2² = 1.2   kg m²

      I₂ = 20 0.4² = 3.2  kg m²

As the body is joined by a rigid rod they both have the same angular velocity

      K = ½ (I₁ + I₂) w²

Let's calculate

      K = ½ (1.2 + 3.2) 5²

       K = 55 J

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Si tenemos tres cubos del mismo tamaño (hierro, madera e icopor). ¿Qué diferencias puede encontrar entre ellos?
cricket20 [7]

Answer: La diferencia es el peso (o la masa), siendo que el cubo de hierro es el mas pesado, después viene el de madera y después el de icopor.

Explanation:

Ok, los 3 cubos tienen el mismo tamaño, lo que implica que tienen el mismo volumen.

Ahora es útil recordar la relación:

Densidad = masa/volumen.

Masa = densidad*volumen.

Nosotros sabemos que la densidad del hierro es mas grande que la de la madera, y la densidad de la madera es mas grande que la del icopor.

Entonces, por la relación anterior, y sabiendo que todos los cubos tienen el mismo volumen, podemos reconocer que el cubo de hierro tiene mayor masa, después viene el de madera y después viene el de icopor.

Y sabiendo que:

masa*gravedad = peso

podemos saber que el cubo mas pesado es el de hierro, después el de madera y después el de icopor.

Además de esta diferencia, también hay otras que no dependen tanto del tamaño del objeto, como pueden ser las capacidades caloríficas, el como reaccionan a campos eléctricos y cosas así que son triviales, pues son diferentes para casi todos los materiales.

5 0
3 years ago
A 900 kg car moves around a 500 m radius curve at 25.0 m/s. What is the centripetal force on
Gnesinka [82]

Answer:

9375 N

Explanation:

From the question,

Centripetal force (F) = mv²/r.................. Equation 1

Where m = mass of the car, v = velocity of the car, r = radius of the curve.

Given: m = 900 kg, r = 600 m, v = 25 m/s

Substitute these values into equation 1

F = (900×25²)/600

F = 9375 N.

Hence the centripetal force on the car is 9375 N

3 0
3 years ago
if you drop a stone from height of 2.5m. what is the speed of the stone right before it hits the ground?
KonstantinChe [14]
Since the stone was dropped from height, its initial velocity = 0 m/s

Using  v² = u² + 2gs.

Where g ≈ 10 m/s²,  u = initial velocity = 0 m/s, s = height from drop = 2.5 m

v² = u² + 2gs

v² = 0² + 2*10*2.5

v² = 0 + 50

v² = 50

v = √50

v ≈ 7.07 m/s

Hence velocity just before hitting the ground is ≈ 7.07 m/s 
6 0
3 years ago
a blackbody is radiating with a characteristic wavelength of 9 microns what is the blackbody temperature answer in kelvin
Daniel [21]

This question involves the concepts of Wein's displacement law and characteristic wavelength.

The blackbody temperature will be "3.22 x 10⁵ k".

<h3>WEIN'S DISPLACEMENT LAW</h3>

According to Wein's displacement law,

\lambda_{max} T = c\\\\T=\frac{c}{\lambda_{max}}

where,

  • \lambda_{max} = characteristic wavelength = 9 μm = 9 x 10⁻⁹ m
  • T = temperature = ?
  • c = Wein's displacment constant = 2.897 x 10⁻³ m.k

Therefore,

T=\frac{2.897\ x\ 10^{-3}\ m.k}{9\ x\ 10^{-9}\ m}

T = 3.22 x 10⁵ k

Learn more about characteristic wavelength here:

brainly.com/question/14650107

7 0
3 years ago
(I think it's D but idontknow)
sukhopar [10]

During an exothermic reaction; light and heat are released into the environment.

An exothermic reaction is one in which heat is released to the environment. This heat can be physically observed sometimes like in an a combustion reaction.

In an exothermic reaction, the enthalpy of the reactants is greater than the enthalpy of the products.

This heat lost is sometimes felt as the hotness of the vessel in which the reaction has taken place.

In conclusion, light and heat are released into the environment in an exothermic reaction.

Learn more: brainly.com/question/4345448

3 0
2 years ago
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