At what rate would heat be lost through the window if you covered it with a 0.750 mm-thick layer of paper (thermal conductivity
1 answer:
The given question is incomplete. The complete question is as follows.
A picture window has dimensions of 1.40 m, 2.50 m and is made of glass 6.00 mm thick. On a winter day, the outside temperature is , while the inside temperature is a comfortable
.
Part A
At what rate is heat being lost through the window by conduction?
Express your answer using three significant figures.
Part B
At what rate would heat be lost through the window if you covered it with a 0.750 mm-thick layer of paper (thermal conductivity 0.0500 W/m?K)?
Express your answer using three significant figures.
Explanation:
Formula for rate of heat transferred through single thick plane of glass is as follows.
=
=
When window is covered by paper then the rate of heat transfer is as follows.
=
=
Thus, we can conclude that heat lost is .
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Answer:
a) k = 200 N/m
b) E = 4 J
c) Δx = 6.3 cm
Explanation:
a)
- In order to find force constant of the spring, k, we can use the the Hooke's Law, which reads as follows:
- where F = 40 N and Δx =- 0.2 m (since the force opposes to the displacement from the equilibrium position, we say that it's a restoring force).
- Solving for k:
b)
- Assuming no friction present, total mechanical energy mus keep constant.
- When the spring is stretched, all the energy is elastic potential, and can be expressed as follows:
- Replacing k and Δx by their values, we get:
c)
- When the object is oscillating, at any time, its energy will be part elastic potential, and part kinetic energy.
- We know that due to the conservation of energy, this sum will be equal to the total energy that we found in b).
- So, we can write the following expression:
- Replacing the right side of (5) with (4), k, m, and v by the givens, and simplifying, we can solve for Δx₁, as follows:
⇒
⇒
Answer:
UV light is more powerful as it has greater energy.
Explanation:
The energy propagated by electromagnetic waves ( light ) through vacuum or medium is known as electromagnetic radiation.
The frequency/wavelength range of electromagnetic radiation is known as electromagnetic spectrum. The electromagnetic spectrum ranging from gamma ray to radio waves.
Frequency range of UV light = ( 8 x 10¹⁴ to 3 x 10¹⁶ ) Hz
Frequency range of Microwaves = ( 300 x 10⁶ to 300 x 10⁹ ) Hz
Ratio of UV light to Microwaves = ( to
)
= ( 2.66 x 10⁶ to 1 x 10⁸ )
Energy of electromagnetic radiation is given by the relation:
E = hν
Here h is plank's constant and ν is frequency.
UV light is more powerful than Microwaves as frequency of UV light is greater than frequency of microwaves. Thus, by the above equation, the energy of UV light is more than energy of Microwaves.