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3 years ago

Which statement correctly describes how thermal energy tends to spontaneously flow?

Physics

2 answers:

eduard3 years ago

8 0

Answer: Option (A) is the correct answer.

Explanation:

The second law of thermodynamics states that heat flows from hot body to a cold body.

A body becomes hot when we heat it at high temperature. Hence, a hotter body will have more collisions between its molecules and thus, there will be maximum kinetic energy between its molecules. Therefore, when this heat moves to a colder body then the molecules of colder body tend to gain some kinetic energy.

And this transfer of heat continues unless and until the temperature of both bodies become equal.

Thus, we can conclude that the statement from high temperature to low temperature correctly describes how thermal energy tends to spontaneously flow.

True [87]3 years ago

5 0

The answer is A. Heat flows from high to low. For example, when you put an ice cube in a hot drink, the heat from the drink goes to the ice cube, and that is why it melts.

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An object example to decrease pressure.

Olin [163]

Answer:

To reduce pressure - decrease the force or increase the area the force acts on. If you were standing on a frozen lake and the ice started to crack you could lie down to increase the area in contact with the ice. The same force (your weight) would apply, spread over a larger area, so the pressure would reduce.

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4 years ago

Read 2 more answers

A massless string connects a 10.00 kg mass to a 13.00 kg cart which is resting on a frictionless horizontal surface. The mass ha

ch4aika [34]

The cart's acceleration to the right after the mass is released is determined as 7.54 m/s².

<h3>Acceleration of the cart</h3>

The acceleration of the cart is determined from the net force acting on the mass-cart system.

Upward force = Downward force

ma = mg

13a = 10(9.8)

13a = 98

a = 98/13

a = 7.54 m/s²

Thus, the cart's acceleration to the right after the mass is released is determined as 7.54 m/s².

Learn more about acceleration here: brainly.com/question/14344386

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6 0

2 years ago

What is the (magnitude of the) centripetal acceleration (as a multiple of g=9.8~\mathrm{m/s^2}g=9.8 m/s 2 ) towards the Eart

Wittaler [7]

Answer:

The centripetal acceleration as a multiple of $g=9.8 m/s^{2}$ is $1.020x10^{-3}m/s^{2}$

Explanation:

The centripetal acceleration is defined as:

$a = \frac{v^{2}}{r}$ (1)

Where v is the velocity and r is the radius

Since the person is standing in the Earth surfaces, their velocity will be the same of the Earth. That one can be determined by means of the orbital velocity:

$v = \frac{2 \pi r}{T}$ (2)

Where r is the radius and T is the period.

For this case the person is standing at a latitude $71.9^{\circ}$ . Remember that the latitude is given from the equator. The configuration of this system is shown in the image below.

It is necessary to use the radius at the latitude given. That radius can be found by means of trigonometric.

$\cos \theta = \frac{adjacent}{hypotenuse}$

$\cos \theta = \frac{r_{71.9^{\circ}}}{r_{e}}$ (3)

Where $r_{71.9^{\circ}}$ is the radius at the latitude of $71.9^{\circ}$ and $r_{e}$ is the radius at the equator ( $6.37x10^{6}m$ ).

$r_{71.9^{\circ}}$ can be isolated from equation 3:

$r_{71.9^{\circ}} = r_{e} \cos \theta$ (4)

$r_{71.9^{\circ}} = (6.37x10^{6}m) \cos (71.9^{\circ})$

$r_{71.9^{\circ}} = 1.97x10^{6} m$

Then, equation 2 can be used

$v = \frac{2 \pi (1.97x10^{6} m)}{24h}$

Notice that the period is the time that the Earth takes to give a complete revolution (24 hours), this period will be expressed in seconds for a better representation of the velocity.

$T = 24h . \frac{3600s}{1h}$ ⇒ $84600s$

$v = \frac{2 \pi (1.97x10^{6} m)}{84600s}$

$v = 146.31m/s$

Finally, equation 1 can be used:

$a = \frac{(146.31m/s)^{2}}{(1.97x10^{6}m)}$

$a = 0.010m/s^{2}$

Hence, the centripetal acceleration is $0.010m/s^{2}$

To given the centripetal acceleration as a multiple of $g=9.8 m/s^{2}$ it is gotten:

$\frac{0.010m/s^{2}}{9.8 m/s^{2}} = 1.020x10^{-3}m/s^{2}$

6 0

3 years ago

The beat your doctor listens to through a sethoscope is the sound of the four values opening

djyliett [7]

and closing .

The heart has 4 valves. They are what makes the lub-dub lub-dub sounds that can be heard from the chest.

The mitral valve is located between the left atrium and the left ventricle. It closes the left atrium to collect oxygenated blood from the lungs and opens to pass it on to the left ventricle.

The tricuspid valve is located between the right atrium and the right ventricle. It closes the right atrium to hold unoxygenated blood and opens to pass it on to the right ventricle ensuring a one way flow.

The aortic valve is located between the aorta and the left ventricle. It closes the left ventricle and opens to the aorta to pass on the oxygen-rich blood to the body.

The pulmonary valve is located between the pulmonary artery and the right ventricle. It closes off the right ventricle and opens to pass on unoxygenated blood to the lungs.

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3 years ago

Two helium-filled balloons are released simultaneously at points A and B on the x axis in an earth-based reference frame. Balloo

Vedmedyk [2.9K]

Answer:

The correct answer is C

Explanation:

In this exercise you are asked to analyze the following situation: for a fixed observer, the two balloons are launched at the same time.

If the observer is mobile moving towards the positive side of axis ax we have several

possibilities when starting the movement

* the observer is to the left of the two balloons

* the observer is between the two balloons

* the observer is to the right of the two baloomls

The time it takes for the signal to arrive to know which ball goes first is

v = d / t

t = d / v

If the signal goes at the speed of light, the speed is a constant and the time will depend only on the distance, so we see that the trigger changes depending on the relative position between a given ball and the observer.

Consequently, it will be seen which comes out first, depending on the relative position with the observer.

The correct answer is C

5 0

4 years ago