All categories

8 months ago

11. Why do dark surfaces absorb radiation better than light surfaces?

1 answer:

7 0

When an electromagnetic wave hits a surface the photons transmit part of the energy to the molecules of the surface. When parts of the electromagnetic waves are reflected depending on the wavelength that is reflected our eyes perceive the object as having a lighter or darker color. The more wavelengths are reflected the lighter the color of the object will be. The more wavelengths are absorbed the darker the object will appear to be. Therefore, those materials that absorb more wavelengths will be dark and those that absorb fewer wavelengths will appear lighter.

You might be interested in

Scientists studying an anomalous magnetic field find that it is inducing a circular electric field in a plane perpendicular to t

yarga [219]

Answer

The rate at which the magnetic field is changing is $[\frac{dB}{dt} ] = 0.000467 T/s$

Explanation

From the question we are told that

The electric field strength is $E = 3.5mV/m = 3.5 *10^{-3} \ V/m$

The radius is $r = 1.5 \ m$

The rate of change of the magnetic field is mathematically represented as

$\frac{d \phi }{dt} = \int\limits^{} {E \cdot dl}$

Where $dl$ is change of a unit length

$\frac{d \phi}{dt} = A * \frac{dB}{dt}$

Where A is the area which is mathematically represented as

$A = \pi r^2$

$E \int\limits^{} { dl} = ( \pi r^2) (\frac{dB}{dt} )$

$E L = ( \pi r^2) (\frac{dB}{dt} )$

where L is the circumference of the circle which is mathematically represented as

$L = 2 \pi r$

$E (2 \pi r ) = (\pi r^2 ) [\frac{dB}{dt} ]$

$E = \frac{r}{2} [\frac{dB}{dt} ]$

$[\frac{dB}{dt} ] = \frac{E}{ \frac{r}{2} }$

substituting values

$[\frac{dB}{dt} ] = \frac{3.5 *10^{-3}}{ \frac{15}{2} }$

$[\frac{dB}{dt} ] = 0.000467 T/s$

8 0

3 years ago

Imagine you have just witnessed a small avalanche on a mountain while skiing, and two slushy snowballs just crashed together in

inn [45]

We have that the momentum p is given by the formula p=mv where m is the mass and v is the velocity. Since for A p=-14kgm/s and m=7, we have that the velocity is -14/7=-2m/s. Hence its speed is 2 m/s.
For b we have that p=15kgm/s and v=3m/s. Because m=p/v, we have m=3kg.
We also have that the momentum is conserved in this system. Hence, the net sum of the momentum of the 2 snowballs equals the momentum of the single giant ball. Hence, p(total)=p(combined)=-14+15=1kgm/s (momentum is a vector; the positive sign means that it tends to the positive direction).

6 0

3 years ago

Read 2 more answers

HEEELLPPPP ME LLELLLLEEAASEEEEEEEEEEEE

irina [24]

Answer:

Valley-river Landslide-Gravity Frost wedging- Glacier Canyon-Ice.

Explanation:

I think that's right

4 0

2 years ago

Which of the following properties of water help to explain why icebergs float in the ocean?

crimeas [40]

The reason why icebergs float in the ocean has to do with temperature. Icebergs are colder than the ocean water and therefore the cold water is less dense than the warm water and this causes the Iceberg to float.

7 0

2 years ago

What is the difference between mutual flux, leakage flux and magnetizing flux

Lemur [1.5K]

In simple words, flux can be stated as the rate of flow of a fluid, radiant energy, or particles across a given area.

Explanation:

Mutual Flux:

The magnetic lines present in among two magnets or solenoid is mutual flux.
These are the lines in which the attraction and repulsion happens.
The SI unit of mutual flux is the Henry

Leakage Flux:

In simple words, it can be stated as the magnetic flux which does not follow the specially designed way in a magnetic circuit.
Leakage flux in the induction motor takes spot due to current runs through the essence of the induction motor.
The SI unit of Leakage flux is the Weber

Magnetizing flux

Magnetic flux is an analysis of the entire magnetic field which moves in a given field
In simple words can be defined as the Magnetic flux is what generates the field around a magnetic material.

The SI unit of magnetic flux is the Weber

3 0

2 years ago