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
DedPeter [7]
3 years ago
5

. The inner and outer surfaces of a 4-m × 7-m brick wall of thickness 30 cm and thermal conductivity 0.69 W/m-K are maintained a

t temperatures of 20 °C and 5 °C, respectively. Determine the rate of heat transfer through the wall, in W.
Physics
1 answer:
Anni [7]3 years ago
4 0

Answer:

\frac{dQ}{dt} = 966 W

Explanation:

As we know that the rate of heat transfer due to temperature difference is given by the formula

\frac{dQ}{dt} = \frac{KA(\Delta T)}{L}

here we know that

K = 0.69 W/m-K

A = 4 m x 7 m

thickness = 30 cm

temperature difference is given as

\Delta T = 20 - 5 = 15 ^oC

now we have

\frac{dQ}{dt} = \frac{(0.69W/m-K)(28 m^2)(15)}{0.30}

\frac{dQ}{dt} = 966 W

You might be interested in
D. A bargain hunter purchases a "gold" crown at a flea market. After she gets home, she hangs it from a scale and finds its weig
s2008m [1.1K]

Answer:

Wc = 7.84    weight of crown

Ww = 7.84 - 6.86 = .98       weight of water displaced

Density = 7.84 / .98 = 8     crown is 8 X that of water

Since gold has a density of 19.3 that of water the crown is certainly not 100 percent (if any) gold  

4 0
2 years ago
Friends who are your age and share the same interests are called
Pie
The answer is C, a peer group.
6 0
3 years ago
Read 2 more answers
An object of known mass M with speed v0 travels toward a wall. The object collides with it and bounces away from the wall in the
Bingel [31]

Neither side of the equation may be used because there are too many unknown quantities before, during, and after the collision

Explanation:

The impulse theorem states that the change in momentum of an object is equal to the impulse, which is the product between the average force applied and the duration of the collision:

\Delta p = F \Delta t

where

\Delta p is the change in momentum

F is the average force

\Delta t is the duration of the collision

In this problem, neither side of the equation can be used to measure the change in momentum. In fact:

- The change in momentum (left side) is given by

\Delta p = m(v-u)

where

m is the mass of the object

u is the initial velocity

v is the final velocity

Here the final velocity is not known, so it's not possible to use this side of the equation

- The impulse (right side) is given by

F\Delta t

here the average force is known, however the duration of the collision is not known, so it's not possible to use this side of the equation.

Learn more about momentum:

brainly.com/question/9484203

#LearnwithBrainly

3 0
3 years ago
Why the blood pressure in human body is greater at the feet than at the brain. please help!!!!​
maxonik [38]

Answer:

The pressure of liquid column is given by p=hpg, where h is depth, p is density and g is acceleration due to gravity.

Therefore, pressure of the liquid column increases with depth. The height of the blood column in a human body is more at feet than at the brain. Therefore, the blood pressure in humans is greater at the feet than the brain.

8 0
3 years ago
Read 2 more answers
John pushes his brother Danny on a skateboard. John applies a force of 29 N and Danny's acceleration is 0.4 m/s
belka [17]

Answer:

50

Explanation:

4 0
3 years ago
Read 2 more answers
Other questions:
  • You are out running and the first mile takes you 10 minutes. The second mile takes you 20 minutes. This is an example of
    9·1 answer
  • Supports combustion is it a chemical or physical property?
    14·2 answers
  • The net force on a rock is 250 newtons downward. The rock accelerates at a rate of 10 m/s2. What is the rock's mass?
    14·1 answer
  • A railroad flatcar is traveling to the right at a speed of 13.0 m/s relative to an observer standing on the ground. someone is r
    5·1 answer
  • Shuffle a deck of cards and turn over the first card. What is the sample space of the experiment? How many outcomes are in the e
    14·1 answer
  • Move the Earth so it is one box from the Sun. (Note: one box side equals about 46,000,000 miles.) Do not change the length of th
    9·1 answer
  • How are the raincoats waterproof? explain​
    13·1 answer
  • In the diagram, q1 and q2 are both +5.00*10^-8 C. What is the electric field at point P? Include a + or - sign to indicate the d
    9·1 answer
  • A ten loop coil of area 0.23 m2 is in a 0.047 T uniform magnetic field oriented so that the maximum flux goes through the coil.
    11·1 answer
  • A force of 1000 newtons was necessary to lift a rock. A total of 3000 joules of work was done. How far was the rock lifted?
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!