1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
GalinKa [24]
3 years ago
6

A Styrofoam box has a surface area of 0.73 m and a wall thickness of 2.0 cm. The temperature of the inner surface is 5.0°C, and

the outside temperature is 25°C. If it takes 8.4 h for 5.0 kg of ice to melt in the container, determine the thermal conductivity of the Styrofoam W/m-K
Physics
1 answer:
Elis [28]3 years ago
5 0

Answer:

K = 0.076 W/m K

Explanation:

Heat required to melt the complete ice is given as

Q = mL

here we have

m = 5.0 kg

L = 3.35 \times 10^5 J/kg

now we have

Q = (5 kg)(3.35 \times 10^5)

Q = 1.67 \times 10^6 J

now the power required to melt ice in 8.4 hours is

P = \frac{Q}{t} = \frac{1.67\times 10^6}{8.4 \times 3600 s}

P = 55.4 Watt

now by formula of conduction we know

P = \frac{KA(\Delta T)}{x}

now we have

55.4 = \frac{K(0.73 m^2)(25 - 5)}{0.02}

K = 0.076 W/m K

You might be interested in
A chemical reaction takes place in which energy is absorbed. Arrange the characteristics of the reaction in order from start to
myrzilka [38]

Let’s create a diagram that shows the chemical reaction absorb energy. Take a look at the diagram I created that is attached to this answer.


Now, the start of the graph line is pretty flat and low leveled. This is the start, which is the reactants. The beginning of a chemical reaction that absorbs energy will almost always start with reactants. I labeled this this “Start: Reactants” and colored the text light green so you can easily detect the part I’m talking about.


Moving on, we see there’s a light blue arrow pointing from the the near bottom to the top curve of the graph line. This is the where the activation energy is rising. Activation energy is the difference between the reactants and products. When the graph line begins to cure, this is when the transition state is beginning. I labeled the transition state, “Transition State” and colored the text a light orange. I colored the line a light blue and also labeled it “Activation Energy” and colored the text light blue as well. I hope it’s easy enough for you to follow along. :)


Next we see that the graph line dips and then goes flat, but it doesn’t go low leveled. It says fairly higher than where it started. This is the end product. I labeled this “End: Product” and colored the text light purple so you can easily detect it.


Okay, now that that’s clear, let’s go ahead and fill in the first blank. According to the diagram we see that the start should be a reactant, and since the graph line starts out pretty low. So, this means that the first tile should be “Low energy of reactants."


Now the second tile should definitely be “Transition State.” This is because the second part in the diagram is transition state. Again, this is mainly where the activation energy is starting to rise.


As for the last and final tile, we should chose “High energy of products.” This is because the diagram is left off on a high leveled part at the end of the graph line.


So, when you place the tiles they should look something like this.


Low energy of reactants

↓

Transition state

↓

High energy of products



- Marlon Nunez

8 0
4 years ago
Read 2 more answers
thr koppean climate map of arizona and three different pictures of cities in arizona describe how ari pressure, temperature and
Sonbull [250]

Answer:

the tempature and the map and climate

Explanation

3 0
4 years ago
Two teams are playing tug of war. Team A pulls to the right with a force of 450 N. Team B pulls to the left with a force of 415
motikmotik

Answer:

35 N to the right.

Explanation:

450 is going to the right so you subtract what is going against it. Which gives you 35. And because 450 is bigger than 415, it'll be going to the right.

6 0
3 years ago
If a car takes a banked curve at less than the ideal speed, friction is needed to keep it from sliding toward the inside of the
PolarNik [594]

Answer:

a. v₁ = 16.2 m/s

b. μ = 0.251

Explanation:

Given:

θ = 15 ° , r = 100 m , v₂ = 15.0 km / h

a.

To determine v₁ to take a 100 m radius curve banked at 15 °

tan θ  = v₁² / r * g

v₁ = √ r * g * tan θ

v₁ = √ 100 m * 9.8 m/s² * tan 15° = 16.2 m/s

b.

To determine μ friction needed for a frightened

v₂ = 15.0 km / h * 1000 m / 1 km * 1h / 60 minute * 1 minute / 60 seg

v₂ = 4.2 m/s

fk = μ * m * g

a₁ = v₁² / r = 16.2 ² / 100 m = 2.63 m/s²

a₂ = v₂² / r = 4.2 ² / 100 m = 0.18 m/s²

F₁ = m * a₁  ,  F₂ = m * a₂

fk = F₁ - F₂   ⇒  μ * m * g = m * ( a₁ - a₂)

μ * g = a₁ - a₂   ⇒  μ = a₁ - a₂ / g

μ = [ 2.63 m/s² - 0.18 m/s² ] / (9.8 m/s²)

μ = 0.251

3 0
4 years ago
An instrument that measures wind speed is called a(n ________.
Oduvanchick [21]
The instrument that measures wind is called anemometer. Anemometer not only measures wind, but also, this measures the direction of the wind. And anemometer is also a common device used in a station weather. It is dervived from the greek work anemos which means wind.
7 0
3 years ago
Other questions:
  • It can be normal for a teen to find some classes challenging, but if a teen has problems in school, as well as frequent absences
    6·2 answers
  • Work equals force the times
    10·1 answer
  • A boat moves initially at 10 m/s, then accelerates at 2 m/s^2 for 10 s. What is the velocity of the boat after 10 s?
    8·1 answer
  • Give 2 ways to increase the temperature of gas ​
    14·1 answer
  • What is the maximum velocity that a 0.3–kilogram mass attached to a 0.75–meter string can have if the mass is whirled around in
    13·1 answer
  • In the school cafeteria, a trouble-making child blows a 12.0 g spitball through a 25.0 cm straw. The force (F) in Newtons, of hi
    14·1 answer
  • PLEASE ANSWER ASAP I will give 30 points
    15·2 answers
  • The gravitational field on Saturn is 10.4 times its value on Earth.
    15·1 answer
  • A bottle of water is taken out of a refrigerator and put on a kitchen table. As the bottle of water warms up, what happens to th
    7·2 answers
  • male lions and human sprinters can both accelerate at about 10.0 m/s2. if a typical lion weighs 170 kg and a typical sprinter we
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!