When an object is fully magnetized, all of its magnetic domains will be ?

A. How many calories are needed to raise the temperature of 1 gram of water by 1 °C?

sweet-ann [11.9K]

A) 1 cal

B) 80 cal

C) 540 cal

Explanation:

A)

The amount of heat energy needed to raise the temperature of a certain mass of a substance is given by

$Q=mC\Delta T$

where

m is the mass of the substance

C is the specific heat capacity

$\Delta T$ is the change in temperature

In this problem:

m = 1 g is the mass of water

$C=1 cal/g^{\circ}C$ is the specific heat capacity of water

$\Delta T=1^{\circ}C$ is the change in temperature

So, the heat needed is

$Q=(1)(1)(1)=1 cal$

B)

For a solid substance at its melting point, the amount of heat needed to melt completely the substance is given by

$Q=m\lambda_f$

where

m is the mass of the substance

$\lambda_f$ is the specific latent heat of fusion of the substance

In this problem:

- The ice is already at melting point, 0 °C

- Mass of the ice: $m=1g$

- Specific latent heat of fusion of ice: $\lambda_f=80 cal/g$

So, the heat needed is

$Q=(1)(80)=80 cal$

C)

For a liquid substance at its boiling point, the amount of heat needed to boil completely the substance is given by

$Q=m\lambda_v$

where

m is the mass of the substance

$\lambda_v$ is the specific latent heat of vaporization of the substance

In this problem:

- The water is already at boiling point, 100 °C

- Mass of the water: $m=1g$

- Specific latent heat of vaporization of water: $\lambda_v=540 cal/g$

So, the heat needed is

$Q=(1)(540)=540 cal$

5 0

3 years ago

Mildred takes a pound of frozen hamburger meat out of the freezer and puts it into the refrigerator.

Hatshy [7]

The meat in the freezer is frozen.
Everything else in the freezer is frozen too.
Nothing in the refrigerator is frozen.
The freezer is colder than the refrigerator. <span>

Mildred takes a pound of frozen hamburger meat out of the freezer
and puts it into the refrigerator. The meat is colder than anything
else that's in there.

Heat flows from the air in the refrigerator into the frozen hamburger (C)
and warms up the meat. When the temperature of the meat warms up
to the temperature of the air in the refrigerator, the heat stops flowing.</span>

7 0

3 years ago

A gas had a initial volume of 168 cm at a temperature of 255 k and a pressure of 1.6 atm the pressure of the gas decreased to 1.

Mademuasel [1]

P₁V₁ / T₁ = P₂V₂ / T₂

1.6 × 168 /255 = 1.3 × V₂ / 285

V₂ = 1.6 × 168 × 285 / (1.3 × 255)

V₂ = 231.095

The final volume = 231 cm³

7 0

3 years ago

2. One mole of a monatomic ideal gas undergoes a reversible expansion at constant pressure, during which the entropy of the gas

Anna35 [415]

Answer:

The initial and final temperatures of the gas is 300 K and 600 K.

Explanation:

Given that,

Entropy of the gas = 14.41 J/K

Absorb gas = 6236 J

We know that,

$ds=\dfrac{dQ}{dt}$

At constant pressure,

$dQ=C_{p}dt$

$\Delta s=\int_{T_{1}}^{T_{2}}{\dfrac{C_{p}dT}{T}}$

$\Delta s=C_{p}ln\dfrac{T_{2}}{T_{1}}$

Put the value into the formula

$14.41=2.5\times8.3144(ln\dfrac{T_{2}}{T_{1}})$

$\dfrac{14.41}{2.5\times8.3144}=ln\dfrac{T_{2}}{T_{1}}$

$0.693=ln\dfrac{T_{2}}{T_{1}}$

$ln2=ln\dfrac{T_{2}}{T_{1}}$

$T_{2}=2T_{1}$ ...(I)

We need to calculate the initial and final temperatures of the gas

Using formula of energy

$\Delta Q=C_{p}\Delta T$

Put the value into the formula

$6236=2.5\times8.3144(T_{2}-T_{1})$

$6236=20.786(T_{2}-T_{1})$

$T_{2}-T_{1}=\dfrac{6236}{20.786}$

$T_{2}-T_{1}=300$

Put the value of T₂

$2T_{1}-T_{1}=300$

$T_{1}=300\ K$

Put the value of T₁ in equation (I)

$T_{2}=2\times300$

$T_{2}=600\ K$

Hence, The initial and final temperatures of the gas is 300 K and 600 K.

8 0

3 years ago

Please answer this question

FinnZ [79.3K]

Answer:

The circuits that were made previously were large and bulky, consisting of circuit components like resistor, capacitor, inductor, transistor, diodes, etc., which were connected with copper wires.

Explanation:

I am in confusion with mono electronic circuit and I am not want to made u confused person.

I am really sorry brother.

:-befrank

4 0

2 years ago