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3 years ago

Why is Energy not created nor destroyed? (Need the answer ASAP!!)

1 answer:

eduard3 years ago

4 0

Since both heat and work can be measured and quantified, this is the same as saying that any change in the energy of a system must result in a corresponding change in the energy of the surroundings outside the system. In other words, energy cannot be created or destroyed.

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A gas expands and does PV work on its surroundings equal to 319 J. At the same time, it absorbs 136 J of heat from the surroundi

LiRa [457]

Answer:

The change in energy of the gas during the process is $-1.83\times 10^{2}$ joules.

Explanation:

We can represent this process by the First Law of Thermodynamics, in which gas does work on its surroundings and absorbs heat from there to describe its change in energy. In other words:

$Q_{in} - W_{out} = \Delta E$

Where:

$Q_{in}$ - Heat absorbed by the gas, measured in joules.

$W_{out}$ - Work done by the gas, measured in joules.

$\Delta E$ - Change in energy, measured in joules.

If we know that $Q_{in} = 1.36\times 10^{2}\,J$ and $W_{out} = 3.19\times 10^{2}\,J$ , the change in energy of the gas is:

$\Delta E = 1.36\times 10^{2}\,J-3.19\times 10^{2}\,J$

$\Delta E = -1.83\times 10^{2}\,J$

The change in energy of the gas during the process is $-1.83\times 10^{2}$ joules.

3 0

3 years ago

To teach you how to find the parameters characterizing an object in a circular orbit around a much heavier body like the earth.

Karolina [17]

Answer:

a) T² = ( $\frac{4\pi ^2}{GM}$ ) r³

b) veloicity the dependency is the inverse of the root of the distance

kinetic energy depends on the inverse of the distance

potential energy dependency is the inverse of distance

angular momentum depends directly on the root of the distance

Explanation:

1) for this exercise we will use Newton's second law

F = ma

in this case the acceleration is centripetal

a = v² / r

the linear and angular variable are related

v = w r

we substitute

a = w² r

force is the universal force of attraction

F = $G \frac{m M}{r^2}$

we substitute

$G \frac{m M}{r^2} = m w^2 r$

w² = $\frac{GM}{r^3}$

angular velocity is related to frequency and period

w = 2π f = 2π / T

we substitute

$( \frac{2\pi }{T} ) = \frac{GM}{r^3}$

the final equation is

T² = () r³

b) the speed of the orbit can be found

v = w r

v = $\sqrt{\frac{GM}{r^3} } \ r$

v = $\sqrt{\frac{GM}{r} }$

in this case the dependency is the inverse of the root of the distance

Kinetic energy

K = ½ M v²

K = ½ M GM / r

K = ½ GM² 1 / r

the kinetic energy depends on the inverse of the distance

Potential energy

U =

U = -G mM / r

dependency is the inverse of distance

Angular momentum

L = r x p

for a circular orbit

L = r p = r Mv

L =

The angular momentum depends directly on the root of the distance

8 0

3 years ago

In your own words, describe why melting ice with salt freezes cream. Compare your descriptions to your classmates and describe h

gizmo_the_mogwai [7]

Answer:

Water normally freezes at 0°C (32°F). Salt lowers the freezing temperature. (That is, it can remain a liquid at much lower temperatures.)

When sprinkled on ice, the salt lowers the freezing temperature of the water which effectively melts the ice when the salt dissolves into it. There is a limit to how low it can reduce the temperature, though. If the temperature drops below -9°C (15°F), it's too cold for the salt to dissolve into the ice.

When making ice cream, the salt lowers the temperature of the ice and water sufficiently enough to freeze the cream.

3 0

3 years ago

What will be the pressure exerterd by the 0bject if 4000n is acting on an area of 50msqure

Ivahew [28]

<h3>Given, </h3>

Force,F = 4000 N

Area,a = 50 m²

Pressure = Force/Area

★ Putting the values in the above formula,we get:

$\sf \rightarrow \: pressure = \dfrac{4000}{50}$

$\sf \rightarrow pressure = 80 \: N {m}^{ - 2}$

7 0

3 years ago

What are the two factors that affect the period of a pendulum?

klemol [59]

The two factors that affect the period of a pendulum are the length of the string and the distance in which the pendulum falls.

Hope this helps! I would greatly appreciate a brainliest! :)

3 0

3 years ago