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3 years ago

Can you make the work output of a machine greater than the work input?

Physics

2 answers:

ExtremeBDS [4]3 years ago

5 0

Answer:

It is impossible to construct a machine which produces the work output greater than the work input.

Let us consider the II law of thermodynamics.

According to Kelvin Plank's statement any engine/machine does not give hundred percent efficiency. And violating the PMM-II(Perpetual motion of machine II kind), Always some amount of energy transferred to the sink or surroundings.

Therefore

W(ouput) = Q₁-Q₂

There are many reasons to lower the work output, just for an example friction between the mating parts reduces the work output.

VLD [36.1K]3 years ago

5 0

Answer:

Explanation:

A machine makes are work easier. The mechanical advantage of a machine tells us the ability of machine to multiply the input force. No machine is 100% efficient. It means it cannot convert all the input completely to output, let alone give a greater output. Some of the work that is input into the machine is always lost in overcoming friction produced.

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1. A signal source has an open-circuit voltage of 1V, and a short-circuit current of10mA. What is the source resistance

LiRa [457]

Answer:

100 Ω

Explanation:

Given that

Open circuit voltage, V = 1 V

Short circuit current, I = 10 mA

Source resistance R, = ?

This is rather a straight forward question. Remember Ohms Law? Current being directly proportional to the voltage and inversely proportional to the resistance?

Yeah, that's the formula we'd be using.

Ohms Law states that V = IR, and thus, if we make R subject of the formula, we have

R = V / I, on substituting the values, we have

R = 1 / 10*10^-3

R = 1 / 0.01

R = 100 Ω

8 0

3 years ago

Half life of a given sample of radium is 22 years the sample will reduce to 25% of its original value after

makkiz [27]

Answer:

44 years

Explanation:

Use half life equation:

A = A₀ (½)^(t / T)

where A is the final amount,

A₀ is the initial amount,

t is time,

and T is the half life.

0.25 A₀ = A₀ (½)^(t / 22)

0.25 = (½)^(t / 22)

t / 22 = 2

t = 44

3 0

3 years ago

A rope of total mass m hnd length L is suspended vertically with an object of mass M suspended from the lower end. Find an expre

pantera1 [17]

Answer:

Part a)

$v = \sqrt{xg + \frac{MLg}{m}}$

Part b)

t = 12 s

Explanation:

Part a)

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$T = \frac{m}{L}xg + Mg$

so the speed of the wave at that position is given as

$v = \sqrt{\frac{T}{\mu}}$

here we know that

$\mu = \frac{m}{L}$

now we have

$v = \sqrt{\frac{ \frac{m}{L}xg + Mg}{m/L}$

$v = \sqrt{xg + \frac{MLg}{m}}$

Part b)

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$t = \int \frac{dx}{\sqrt{xg + \frac{MLg}{m}}}$

$t = \frac{1}{g}(2\sqrt{xg + \frac{MLg}{m}})$

$t = \frac{2}{9.8}(\sqrt{(39.2\times 9.8) + \frac{8(39.2)(9.8)}{1}})$

$t = 12 s$

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3 years ago

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jarptica [38.1K]

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3 years ago

All biomes don’t have the same level of biodiversity. What seems to be the optimal conditions for high biodiversity?

irinina [24]

Answer:

See the answer below

Explanation:

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Consequently, it follows logically that the optimal conditions for high biodiversity would be a warm temperature of above 18 $^oC$ and wet environment with annual precipitation of not less than 262 cm.

The variation in temperature and precipitation across biomes can thus be said to be responsible for the variation in the level of biodiversity in them.

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3 years ago