All categories

11 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

Choose all the answers that apply.

slava [35]

<h2>So, the correct answers are:</h2>

Travels in longitudinal waves

Travels most slowly through a gas

Speeds up when temperature is increased

Is caused by vibration

Explanation for correct answers:

Yes, it does travel in longitudinal waves

Yes, sounds weird, but travels faster in the water

Yes, does speed up when temperature is increased

And yes, Is caused by vibration.

<h2>Wrong answer is:</h2>

Can travel through a vacuum

Explanation for wrong answer:

actually, in space, there is NO sound, because there are no particals for the sound to vibrate with, there's just empty SPACE.

5 0

2 years ago

A 560-g squirrel with a surface area of 930cm2 falls from a 5.0-m tree to the ground. Estimate its terminal velocity. (Use a dra

bija089 [108]

Explanation:

Terminal velocity is given by:

$v_t=\sqrt{\frac{2mg}{\rho C_dA}}$

Here, m is the mass of the falling object, g is the gravitational acceleration, $C_d$ is the drag coefficient, $\rho$ is the fluid density through which the object is falling, and A is the projected area of the object. in this case the projected area is given by:

$A=\frac{A_s}{2}=\frac{930cm^2}{2}=465cm^2\\465cm^2*\frac{1m^2}{10^4cm^2}=0.0465m^2\\560g*\frac{1kg}{10^3g}=0.56kg$

Recall that drag coefficient for a horizontal skydiver is equal to 1 and air density is $1.28\frac{kg}{m^3}$ .

$v_t=\sqrt{\frac{2(0.56kg)(9.8\frac{m}{s^2})}{(1.28\frac{kg}{m^3}(1)(0.0465m^2)}}\\v_t=13.58\frac{m}{s}$

Without drag contribution the motion of the person is an uniformly accelerated motion, thus:

$v_f^2=v_o^2+2gh\\v_f=\sqrt{2gh}\\v_f=\sqrt{2(9.8\frac{m}{s^2})(5m)}\\v_f=9.9\frac{m}{s}$

7 0

2 years ago

hello friends,i need your help my home work now in physics,topic:motion.40 marks +brainliest if correct .

fenix001 [56]

Answer:

See below

Explanation:

Vertical position is given by

df = do + vo t - 1/2 a t^2 df = final position = 0 (on the ground)

do =original position = 2 m

vo = original <u>VERTICAL</u> velocity = 0

a = acceleration of gravity = 9.81 m/s^2

THIS BECOMES

0 = 2 + 0 * t - 1/2 ( 9.81)t^2

to show t =<u> .639 seconds to hit the ground </u>

During this .639 seconds it flies horizontally at 10 m/s for a distance of

10 m/s * .639 s =<u> 6.39 m </u>

5 0

1 year ago

Which component of weight is cause for S.H.M of bob simple pendulum

jeka57 [31]

Explanation:

The Simple Pendulum. A simple pendulum is defined to have a point mass, also known as the pendulum bob, which is suspended from a string of length L with negligible mass ((Figure)). Here, the only forces acting on the bob are the force of gravity (i.e., the weight of the bob) and tension from the string.

hope it helps you

6 0

2 years ago

The swim bladder of a fish helps keep the fish from sinking by_______.

Slav-nsk [51]

Answer:

C. Increasing its buoyancy

6 0

2 years ago

Read 2 more answers