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
Novay_Z [31]
3 years ago
12

How does a vacuum flask keep drinks hot? Explain in terms of conduction, convection and radiation.

Physics
1 answer:
Flura [38]3 years ago
4 0
Vacum flask has inner layer of glass and outer body of plastic.the glass has a reflective metal layer..when a hot drink is poured into the flask it prevents conduction.tight lid stops the convection.when radiation tries to leave the hot drink the reflective layer of the glass reflects it back so no heat can escape.
You might be interested in
If an object 18 millimeters high is placed 12 millimeters from a diverging lens and the image is formed 4 millimeters in front o
tangare [24]
The correct answer is letter A. 6 millimeters. <span>If an object 18 millimeters high is placed 12 millimeters from a diverging lens and the image is formed 4 millimeters in front of the lens, the height of the image is 6 millimeters.
</span>
Solution:
18 / x = 12 / 4 
12x = 72
x = 6mm
7 0
3 years ago
An auditorium measures 43.0m × 18.0m × 15.0m. The density of air is 1.20 kg/m3. What is the volume of the room in cubic feet? (D
frez [133]
The question here would be what is the volume of the room. The density of air that is given has no use. We simply multiply the dimensions given of the room to determine  the volume.

<span>43.0m × 18.0m × 15.0m = 11610m^3 ( 3.28 ft / 1 m)^3 = 4.09 x 10^5 ft^3</span>
5 0
3 years ago
A parallel-plate capacitor with plates of area 360 cm2 is charged to a potential difference V and is then disconnected from the
Softa [21]

Answer:

Q=3.9825\times 10^{-9} C

Explanation:

We are given that a parallel- plate capacitor is charged to a potential difference V and then disconnected from the voltage source.

1 m =100 cm

Surface area =S=\frac{360}{10000}=0.036 m^2

\Delta d=0.8 cm=0.008 m

\Delta V=100 V

We have to find the charge Q on the positive plates of the capacitor.

V=Initial voltage between plates

d=Initial distance between plates

Initial Capacitance of capacitor

C=\frac{\epsilon_0 S}{d}

Capacitance of capacitor after moving plates

C_1=\frac{\epsilon_0 S}{(d+\Delta d)}

V=\frac{Q}{C}

Potential difference between plates after moving

V=\frac{Q}{C_1}

V+\Delta V=\frac{Q}{C_1}

\frac{Qd}{\epsilon_0S}+100=\frac{Q(d+\Delta d)}{\epsilon_0S}

\frac{Q(d+\Delta d)}{\epsilon_0 S}-\frac{Qd}{\epsilon_0S}=100

\frac{Q\Delta d}{\epsilon_0 S}=100

\epsilon_0=8.85\times 10^{-12}

Q=\frac{100\times 8.85\times 10^{-12}\times 0.036}{0.008}

Q=3.9825\times 10^{-9} C

Hence, the charge on positive plate of capacitor=Q=3.9825\times 10^{-9} C

6 0
3 years ago
5. A box weighs 196 N. A rope is tied to the box. What is the
natta225 [31]

Answer:

296 N

Explanation:

Draw a free body diagram.  The box has two forces on it: tension up and weight down.

Apply Newton's second law:

∑F = ma

T − mg = ma

T = m (g + a)

Given m = 196 N / 9.8 m/s² = 20 kg, and a = +5 m/s²:

T = (20 kg) (9.8 m/s² + 5 m/s²)

T = 296 N

5 0
3 years ago
Please answer help me
Andrews [41]
I believe the answer is x
7 0
3 years ago
Other questions:
  • How many revolutions per minute would a 25 m -diameter ferris wheel need to make for the passengers to feel "weightless" at the
    9·1 answer
  • The election of 2008 had a record-breaking number of voters. It had the highest percentage of eligible voters voting in more tha
    8·1 answer
  • a uniform disc and hollow right circular cone have the same formula for their moment of inertia when rotating about the central
    10·1 answer
  • What are the standard units of length, mass, and volume in the<br> metric system?
    7·1 answer
  • What is its moment of inertia about an axis that passes through its center?
    14·1 answer
  • A parallel-plate capacitor, made of two circular plates of radius R - 10 cm, is connected in series 2 with a resistor of resista
    5·1 answer
  • Determine the final angular velocity of a particle that rotates 4500 ° in 3 seconds and an angular acceleration of 8 Rad / s ^ 2
    14·1 answer
  • Thirty beats are heard in one minute when two notes are played together. If the higher note has a frequency of 740 Hz, what is t
    14·1 answer
  • Place the following types of electromagnetic radiation in order from LOWEST energy
    14·1 answer
  • In a game of Tug-of-War,
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!