Ask question

Ask question

All categories

3 years ago

13

When thermal insulation, such as spun glass or rock wool, is placed beneath the roof of a house, then in cold weather the insula

tion will:_______.A. create heat to warm the house.B. keep the cold from coming through the roof.C. slow the flow of heat from inside the house to the outside.D. stop the flow of heat from inside the house to the outside.

2 answers:

siniylev [52]3 years ago

7 0

Answer:

c. slow the flow of heat from inside the house to the outside.

Explanation:

Thermal insulation not completely stops the flow of heat but slow down the process of flowing of heat from inside the house to the outside.

Kipish [7]3 years ago

6 0

Answer:

bababooey

Explanation

bababooey

You might be interested in

Calculate the energy of a photon having a wavelength in thefollowing ranges.(a) microwave, with λ = 50.00 cmeV(b) visible, with

IgorLugansk [536]

(a) $2.5\cdot 10^{-6}eV$

The energy of a photon is given by:

$E=\frac{hc}{\lambda}$

where

$h=6.63\cdot 10^{-34}Js$ is the Planck constant

$c=3\cdot 10^8 m/s$ is the speed of light

$\lambda$ is the wavelength

For the microwave photon,

$\lambda=50.00 cm = 0.50 m$

So the energy is

$E=\frac{(6.63\cdot 10^{-34}Js)(3\cdot 10^8 m/s)}{0.50 m}=4.0\cdot 10^{-25} J$

And converting into electronvolts,

$E=\frac{4.0\cdot 10^{-25}J}{1.6\cdot 10^{-19} J/eV}=2.5\cdot 10^{-6}eV$

(b) $2.5 eV$

For the energy of the photon, we can use the same formula:

$E=\frac{hc}{\lambda}$

For the visible light photon,

$\lambda=500 nm = 5 \cdot 10^{-7}m$

So the energy is

$E=\frac{(6.63\cdot 10^{-34}Js)(3\cdot 10^8 m/s)}{5\cdot 10^{-7} m}=4.0\cdot 10^{-19} J$

And converting into electronvolts,

$E=\frac{4.0\cdot 10^{-19}J}{1.6\cdot 10^{-19} J/eV}=2.5 eV$

(c) $2500 eV$

For the energy of the photon, we can use the same formula:

$E=\frac{hc}{\lambda}$

For the x-ray photon,

$\lambda=0.5 nm = 5 \cdot 10^{-10}m$

So the energy is

$E=\frac{(6.63\cdot 10^{-34}Js)(3\cdot 10^8 m/s)}{5\cdot 10^{-10} m}=4.0\cdot 10^{-16} J$

And converting into electronvolts,

$E=\frac{4.0\cdot 10^{-16}J}{1.6\cdot 10^{-19} J/eV}=2500 eV$

6 0

3 years ago

A resistor, inductor, and a battery are arranged in a circuit. The circuit has an inductance of L = 1 H and a resistance of 1.4

shtirl [24]

Answer:

$\tau \approx 7.14 \times 10^{-4}s \approx0.714ms$

Explanation:

In a LC circuit The time constant τ is the time necessary for 60% of the total current (maximum current), pass through the inductor after a direct voltage source has been connected to it. The time constant can be calculated as follows:

$\tau =\frac{L}{R}$

Therefore, the time needed for the current to reach a fraction f = 0.6(60%) of its maximum value is:

$\tau =\frac{1}{1.4\times 10^{3}} =7.142857143 \times 10^{-4} \approx7.14 \times 10^{-4}s$

8 0

4 years ago

72) What is the freezing point (°C) of a solution prepared by dissolving 11.3 g of Ca(NO3)2 (formula weight = 164 g/mol) in 115

Rina8888 [55]

<u>Answer:</u> The freezing point of solution is -3.34°C

<u>Explanation:</u>

Vant hoff factor for ionic solute is the number of ions that are present in a solution. The equation for the ionization of calcium nitrate follows:

$Ca(NO_3)_2(aq.)\rightarrow Ca^{2+}(aq.)+2NO_3^-(aq.)$

The total number of ions present in the solution are 3.

To calculate the molality of solution, we use the equation:

$Molality=\frac{m_{solute}\times 1000}{M_{solute}\times W_{solvent}\text{ in grams}}$

Where,

$m_{solute}$ = Given mass of solute $(Ca(NO_3)_2)$ = 11.3 g

$M_{solute}$ = Molar mass of solute $(Ca(NO_3)_2)$ = 164 g/mol

$W_{solvent}$ = Mass of solvent (water) = 115 g

Putting values in above equation, we get:

$\text{Molality of }Ca(NO_3)_2=\frac{11.3\times 1000}{164\times 115}\\\\\text{Molality of }Ca(NO_3)_2=0.599m$

To calculate the depression in freezing point, we use the equation:

$\Delta T=iK_fm$

where,

i = Vant hoff factor = 3

$K_f$ = molal freezing point depression constant = 1.86°C/m.g

m = molality of solution = 0.599 m

Putting values in above equation, we get:

$\Delta T=3\times 1.86^oC/m.g\times 0.599m\\\\\Delta T=3.34^oC$

Depression in freezing point is defined as the difference in the freezing point of water and freezing point of solution.

$\Delta T=\text{freezing point of water}-\text{freezing point of solution}$

$\Delta T$ = 3.34 °C

Freezing point of water = 0°C

Freezing point of solution = ?

Putting values in above equation, we get:

$3.34^oC=0^oC-\text{Freezing point of solution}\\\\\text{Freezing point of solution}=-3.34^oC$

Hence, the freezing point of solution is -3.34°C

4 0

4 years ago

What are the 4 forces that are at work within the nucleus of an atom

postnew [5]

<span>Electromagnetic, Strong Nuclear, Weak Nuclear, and Gravity</span>

8 0

3 years ago

A man walks for 2 hours at a speed of 3m/s. How far does he travel?

Scorpion4ik [409]

First you get the data:

Velocity (v) = 3m/s
Distance (d) = ??
Time (t) = 2hr

Time conversion: hours to seconds:

1 hour = 3600 seconds

$\bf{2\not{h}*\left(\dfrac{3600 \ seg}{1\not{h}}\right)=7200 \ seg }$

We calculate the distance, using the formula:

$\bf{d=t*v }$

$\bf{d=3600\not{seg}*3\frac{m}{\not{m}} }$

$\bf{d=21600 \ m}$

Answer: I travel to 21600 meters.

6 0

2 years ago