What is the velocity of a wave with a frequency of 760Hz and a wavelength of 0.45m?

The energy of a photon is proportional to its a) amplitude. d) wave number, k-2m/A c) velocity. b) frequency

Scilla [17]

Answer:

Frequency

Explanation:

Photons are the packet of energy. They are massless and chargeless particles. They travel in the vacuum with the speed of light. The energy of photon is given by :

$E=h\nu$

Where

h = Planck's constant

$\nu$ = frequency of photon

Or $E=\dfrac{hc}{\lambda}$

c = speed of light

$\lambda$ = wavelength of photon

From the above equation, it is clear that the energy of photon is directly proportional to its frequency.

5 0

3 years ago

For what angle of incidence at the first mirror will this ray strike the midpoint of the second mirror (which is s=29.0cm long)

Lesechka [4]

The question is missing a diagram of the ray reflection. I attached a diagram which comes from a similar question in the answer section. The full question should be as follows:

Two plane mirrors intersect at right angles. A laser beam strikes the first of them at a point d = 10.0cmfrom their point of intersection, as shown in the figure. For what angle of incidence at the first mirror will this ray strike the midpoint of the second mirror (which is s=29.0cm long) after reflecting from the first mirror?

Answer:

34.6°

Explanation:

To strike the midpoint of the second mirror, the ray light will have to travel half of the distance vertically

i.e. 29/2 = 14.5

We can solve this through trigonometry.

Let the angle between the ray and the vertical plane mirror is known as α

tan α = 10/14.5

α = $tan^{-1} (10/14.5)$ = 34.6°

The angle of incidence is the angle between the ray and the normal line of the mirror.

Let angle of incidence of first mirror be β

β = α = 34.6

6 0

3 years ago

A rocket has landed on Planet X, which has half the radius of Earth. An astronaut onboard the rocket weighs twice as much on Pla

Burka [1]

Explanation:

Let acceleration due to Gravity for a planet is given by:

$g_X=GM/R^2$

Here, $g_X = 2g$

Escape velocity is given by:

$v =\sqrt{ \frac{2GM} {R}} = \sqrt{2aR}$

Here, $R=R_earth/2$

and g_X = 2g

Therefore, $v=\sqrt(2(2g)(R/2))=v_0$

7 0

3 years ago

A horizontal spring with spring constant 130 N/m is compressed 17 cm and used to launch a 2.8 kg box across a frictionless, hori

olasank [31]

Explanation:

The given data is as follows.

k = 130 N/m, $\Delta x$ = 17 cm = 0.17 m (as 1 m = 100 cm)

mass (m) = 2.8 kg

When the spring is compressed then energy stored in it is as follows.

Energy = $\frac{1}{2}kx^{2}$

Now, spring energy gets converted into kinetic energy when the box is launched.

So, $\frac{1}{2}kx^{2}$ = $\frac{1}{2}mv^{2}$

$\frac{1}{2} \times 130 \times (0.17)^{2}$ = $\frac{1}{2} \times 2.8 \times v^{2}$

$v^{2} = \frac{3.757}{2.8}$

= 1.34

v = 1.15 m/sec

Now,

Frictional force = $\mu \times mg$

= $0.15 \times 2.8 \times 9.8$

= 4.116 N

Also, Kinetic energy = work done by friction

$\frac{1}{2}mv^{2} = F_{f} \times d$

$\frac{1}{2} \times 2.8 \times (1.15)^{2} = 4.116 \times d$

1.8515 = $4.116 \times d$

d = 0.449 m

Thus, we can conclude that the box slides 0.449 m across the rough surface before stopping.

8 0

3 years ago

Why are TV shows nowadays so boring?

Anna [14]

The answer is a matter of opinion, and you're going to get different answers
from different people. Here's my take on it:

The writers, producers and advertising sponsors of these shows certainly
don't think they're boring. And definitely neither do the TV networks that
decide which ones to broadcast.

I'm not trying to say "The experts don't think they're boring, so you must
be wrong". I'm trying to say that different people have different opinions
about the same shows, and in your case, you find them boring.

My conclusion is this:
I think you're finding TV shows boring nowadays because you're growing
as a person. You've grown, developed, and matured to the point where
you're above the level of audience that the shows are pitched for. That's
a very good thing !

You're sad because you used to get pleasure and entertainment from TV,
and now it doesn't give you those things. That's like losing an old friend,
that you used to have such fun playing with, but he just doesn't do it for
you any more.

Now that you've grown up, you've made new friends. With them, you do
things that you wouldn't even understand with your younger friends. And
you develop new interests, like ... I don't know ... books, movies, hobbies,
your church, your profession, learning new things, developing new skills,
exercising your brain, writing, volunteer work, ham radio, building fine
furniture, singing, learning to write music, raising tropical plants, sculpture,
politics ... whatever turns you on. Some people never grow past the stage
where staring at the tube is all they need in life, because they don't have
what it takes to be interested in anything else. Those are the people that
TV is aimed at. But you have more, and that's why TV isn't enough for you.

There are other possible reasons why TV bores you. But until I know more
about you, I think it's a very, very good sign.

3 0

3 years ago

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