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3 years ago

How many calories are needed to raise the temperature of 2g of water 3 C?

Physics

1 answer:

olga nikolaevna [1]3 years ago

8 0

Answer:

The number of calories needed is 6c.

Explanation:

The amount of energy $Q$ needed to raise the temperature $\Delta T$ of water of mass $m$ is

$Q = mC\Delta T$

where $C = 1cal/g\cdot C$ is the specific heat capacity of water.

Putting in numbers into equation (1), we get:

$Q = (2g)(1)(3^oC )\\$

$\boxed{Q = 6\:cal }$

which is the number of calories needed.

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Write a numerical expression for the emissive intensity (in W/m^2.sr) coming out of a tiny hole in an enclosure of surface tempe

stiks02 [169]

Answer:

6.0 × $10^{11}$ W/ $m^{2}$

Explanation:

From Wien's displacement formula;

Q = e A $T^{4}$

Where: Q is the quantity of heat transferred, e is the emissivity of the surface, A is the area, and T is the temperature.

The emissive intensity = $\frac{Q}{A}$ = e $T^{4}$

Given from the question that: e = 0.6 and T = 1000K, thus;

emissive intensity = 0.6 × $(1000)^{4}$

= 0.6 × 1.0 × $10^{12}$

= 6.0 × $10^{11}$ $\frac{W}{m^{2} }$

Therefore, the emissive intensity coming out of the surface is 6.0 × $10^{11}$ W/ $m^{2}$ .

3 0

3 years ago

A bubble of air is rising up through the ocean. When it is at a depth of 20.0 m below the surface, where the temperature is 5.00

kotegsom [21]

Answer:

the volume is 0.253 cm³

Explanation:

The pressure underwater is related with the pressure in the surface through Pascal's law:

P(h)= Po + ρgh

where Po= pressure at a depth h under the surface (we assume = 1atm=101325 Pa) , ρ= density of water ,g= gravity , h= depth at h meters)

replacing values

P(h)= Po + ρgh = 101325 Pa + 1025 Kg/m³ * 9.8 m/s² * 20 m = 302225 Pa

Also assuming that the bubble behaves as an ideal gas

PV=nRT

where

P= absolute pressure, V= gas volume ,n= number of moles of gas, R= ideal gas constant , T= absolute temperature

therefore assuming that the mass of the bubble is the same ( it does not absorb other bubbles, divides into smaller ones or allow significant diffusion over its surface) we have

at the surface) PoVo=nRTo

at the depth h) PV=nRT

dividing both equations

(P/Po)(V/Vo)=(T/To)

V=Vo*(Po/P)(T/To) = 0.80 cm³ * (101325 Pa/302225 Pa)*(277K/293K) = 0.253 cm³

V = 0.253 cm³

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3 years ago

The aorta pumps blood out of the heart to the rest of the body. Please select the best answer from the choices provided. T or f

Daniel [21]

The left ventricle relaxes and fills up with blood before squeezing and pumping the oxygen-rich blood through the aortic valve into the aorta — the main artery that carries blood to your body.<u>TRUE</u>

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3 years ago

Read 2 more answers

Who was the 43rd First Lady?

atroni [7]

Answer: After serving as Second Lady from 1981 to 1989, Barbara Pierce Bush served as First Lady of the United States when her husband George H. W. Bush won the Presidency. She is also the mother of the 43rd President, George W. Bush, and of Florida's 43rd Governor, Jeb Bush.

Explanation:

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3 years ago

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Nadusha1986 [10]

Answer:

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Explanation:

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3 years ago