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3 years ago

How much energy becomes unavailable for work in an isothermal process at 440 k, if the entropy increase is 25 j/k?

1 answer:

8 0

Answer: 11,000 J

Explanation:

In an isothermal process,

$\text{entropy increase} = \frac{\text{amount of energy in heat transfer}}{\text{temperature} }$ (1)

Note that, the energy used in heat transfer is not available for work. So, the amount of energy unavailable for work is equal to the energy used in heat transfer.

To obtain the amount of energy in heat transfer, we multiply both sides of equation (1) by the denominator of the right side of (1) so that

amount of energy in heat transfer = (entropy increase)(temperature)
= (25 J/K)(440 K)
= 11,000 J

Since the amount of energy unavailable for work is equal to the amount of energy in the heat transfer, therefore the amount of energy unavailable for work is 11,000 J.

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A steer must eat at least 100 pounds of grain to gain less than 10 pounds of muscle tissue. This illustrates Group of answer cho

Setler79 [48]

Answer:

the second law of thermodynamics. that some energy is destroyed in every energy conversion.

Explanation:

According to the second law of thermodynamics, energy conversion is never 100% efficient. Some energy is always lost as it is being converted from one form to the other.

The fact that a steer must eat at least 100 pounds of grain to gain less than 10 pounds of muscle tissue shows that not all the energy taken up from the grain is channelled towards building the muscle tissue. Some energy from the grains are lost on the way according to the second law of thermodynamics.

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3 years ago

A 10 kg monkey climbs up a massless rope that runs over a frictionless tree limb and back down to a 15 kg package on the ground.

pshichka [43]

Answer:

A. 4,9 m/s2

B. 2,0 m/s2

C. 120 N

Explanation:

In the image, 1 is going to represent the monkey and 2 is going to be the package. Let a_mín be the minimum acceleration that the monkey should have in the upward direction, so the package is barely lifted. Apply Newton’s second law of motion:

$\sum F_y=m_1*a_m_i_n = T-m_1*g$

If the package is barely lifted, that means that T=m_2*g; then:

$\sum F_y =m_1*a_m_i_n=m_2*g-m_1*g$

Solving the equation for a_mín, we have:

$a_m_i_n=((m_2-m_1)/m_1)*g = ((15kg-10kg)/10kg)*9,8 m/s^2 =4,9 m/s^2$

Once the monkey stops its climb and holds onto the rope, we set the equation of Newton’s second law as it follows:

For the monkey: $\sum F_y = m_1*a \rightarrow T-m_1*g=m_1*a$

For the package: $\sum F_y = m_2*a \rightarrow m_2*g - T = m_2*a$

The acceleration a is the same for both monkey and package, but have opposite directions, this means that when the monkey accelerates upwards, the package does it downwards and vice versa. Therefore, the acceleration a on the equation for the package is negative; however, if we invert the signs on the sum of forces, it has the same effect. To be clearer:

For the package: $\sum F_y = -m_2*a \rightarrow T-m2*g=-m_2*a \rightarrow m_2*g -T=m_2 *a$

We have two unknowns and two equations, so we can proceed. We can match both tensions and have:

$m_1*a+m_1*g=m_2*g-m_2*a$

Solving a, we have

$(m_1+m_2)*a =(m_2 - m1)*g\\\\a=((m_2-m_1)/(m_1+m_2))*g \rightarrow a=((15kg-10kg)/(10kg+15kg))*9,8 m/s^2\\\\a= 2,0 m/s^2$

We can then replace this value of a in one for the sums of force and find the tension T:

$T = m_1*a+m_1*g \rightarrow T=m_1*(a+g)\\\\T = 10kg*(2,0 m/s^2+9,8 m/s^2) \\\\T = 120 N$

5 0

3 years ago

A town is considering building a biodiesel power plant that would burn biomass to generate electricity. Which of the following c

zmey [24]

Answer: it reduces dependence on fossil fuels. Disadvantage: it would emit pollution into the air.

3 0

3 years ago

A body 'A' of mass 1.5kg travelling along the positive X-axis with speed of 4.5m/s collides with another body 'B' of mass 3.2kg,

xz_007 [3.2K]

I already answered this question.
Please refer to this link brainly.com/question/8743596.

6 0

3 years ago

What has been happening to the cosmic microwave background radiation since the Big Bang?

kondor19780726 [428]

Answer:

Explanation:

Cosmologists refer to a "surface of last scattering" when the CMB photons last hit matter; after that, the universe was too big. So when we map the CMB, we are looking back in time to 380,000 years after the Big Bang, just after the universe was opaque to radiation. But the CMB was first found by accident.

plz mark as brainliest

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3 years ago