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
Aleksandr [31]
3 years ago
12

A two-dimensional crystal has a rectangular unit cell, with spacings between the centers of the atoms of 0.5 nm in one direction

(e.g., the x direction), and 0.4 nm in the other direction (e.g., the y direction). Presuming that the crystal has 1000 unit cells in each direction, sketch a representative portion of the reciprocal lattice on a scale drawing, showing the dimensions, units, and directions (i.e., kx and ky)
Physics
1 answer:
pav-90 [236]3 years ago
6 0

So directly the cell density value in a rectangle is:

5*10^{17} cells/cm^{2}

In this exercise, we must first calculate the area of ​​the rectangle, remembering that you need to convert from nm to cm is:

A=B*H\\A=(0.4*10^{-7})*(0.5*10^{-7})= 2*10^{-15}

Next, let's calculate the density from the calculated area:

\frac{N}{A} = \frac{1000}{2*10^{-15} } = 5*10^{17}

In this way, the calculation represents that there is:

5*10^{17} cells/cm^{2}

Learn more: brainly.com/question/18320053

You might be interested in
Find the hiker’s gravitational potential energy if the cliff is 60m high
Furkat [3]

Answer:

Potential energy is U=mgh

Explanation:

The potential energy depends on the mass, the acceleration of gravity g and the height at which the object or person is.

Potential energy  U=mgh

In this case we would need to know the exact mass of the hiker in order to calculate the potential energy.

But we know the values of g and h

g=9.81m/s^2

h=60m

So, the potential energy

U=m(9.81m/s^2)(60m)\\\\U=588.6*m

m is the mass of the hiker, wich is not in the description of the problem.

4 0
3 years ago
At the county fair, Chris throws a 0.12kg baseball at a 2.4kg wooden milk bottle, hoping to knock it off its stand and win a pri
viva [34]

Answer:

v_{f2} =6.5%v_{i1}

Explanation:

Mass of the ball: m_{1} =0.12kg]

Initial velocity of the ball:   v_{i1}

final velocity of the ball: v_{f1} which is -30/100 of v_{i1} =-0.3v_{i1}

Mass of the bottle: m_{2} =2.4kg

Initial velocity of the bottle: v_{i2}=0m/s

final velocity of the bottle: v_{f2} is unknown (to find)

<em>by using conservation momentum, which stated that the initial momentum is equal to the final momentum.</em>

<em />m_{1} v_{i1} +m_{2} v_{i2} =m_{1} v_{f1} +m_{2} v_{f2}<em />

<em>so since the bottle is at rest firstly, therefore </em>v_{i2} =0<em />

<em />m_{1} v_{i1} +m_{2} (0) =m_{1} v_{f1} +m_{2} v_{f2}<em />

<em />m_{1} v_{i1}  =m_{1} v_{f1} +m_{2} v_{f2}<em>         </em><em>equation 1</em>

so now substitute v_{f1} into equation 1

m_{1} v_{i1}  =m_{1} (-0.3v_{i1} ) +m_{2} v_{f2}

<em />m_{1} v_{i1}  = -0.3m_{1}v_{i1}  +m_{2} v_{f2}<em />

<em>collect the like terms</em>

m_{1} v_{i1}   +0.3m_{1}v_{i1}  =m_{2} v_{f2}

1.3m_{1} v_{i1}   =m_{2} v_{f2}

divide both  side by m_{2}

v_{f2}=\frac{1.3m_{1} v_{i1}}{m_{2} }

Now substitute

v_{f2} =\frac{1.3*0.12*v_{i1}}{2.4}\\v_{f2}    =\frac{0.156v_{i1} }{2.4} \\v_{f2} =0.065v_{i1}

v_{f2} =6.5%v_{i1}

<em />

6 0
3 years ago
Read 2 more answers
A running mountain lion can make a leap 10.0 m long, reaching a maximum height of 3.0 m.?a.What is the speed of the mountain lio
Arisa [49]

Answer:

What is the speed of the mountain lion as it leaves the ground?

9.98m/s

At what angle does it leave the ground?

50.16°

Explanation:

This is going to be long, so if you want to see how it was solved refer to the attached solution. If you want to know the step by step process, read on.

To solve this, you will need use two kinematic equations and SOHCAHTOA:

d = v_it + \dfrac{1}{2}at^{2}\\\\vf = vi + at

With these formulas, we can derive formulas for everything you need:

Things you need to remember:

  • A projectile at an angle has a x-component (horizontal movement) and y-component (vertical movement), which is the reason why it creates an angle.
  • Treat them separately.
  • At maximum height, the vertical final velocity is always 0 m/s going up. And initial vertical velocity is 0 m/s going down.
  • Horizontal movement is not influenced by gravity.
  • acceleration due to gravity (a) on Earth is constant at 9.8m/s

First we need to take your given:

10.0 m long (horizontal) and maximum height of 3.0m (vertical).

d_x=10.0m\\d_y=3.0m

What your problem is looking for is the initial velocity and the angle it left the ground.

Vi = ?     Θ =?

Vi here is the diagonal movement and do solve this, we need both the horizontal velocity and the vertical velocity.

Let's deal with the vertical components first:

We can use the second kinematic equation given to solve for the vertical initial velocity but we are missing time. So we use the first kinematic equation to derive a formula for time.

d_y=V_i_yt+\dfrac{1}{2}at^{2}

Since it is at maximum height at this point, we can assume that the lion is already making its way down so the initial vertical velocity would be 0 m/s. So we can reduce the formula:

d_y=0+\dfrac{1}{2}at^{2}

d_y=\dfrac{1}{2}at^{2}

From here we can derive the formula of time:

t=\sqrt{\dfrac{2d_y}{a}}

Now we just plug in what we know:

t=\sqrt{\dfrac{(2)(3.0m}{9.8m/s^2}}\\t=0.782s

Now that we know the time it takes to get from the highest point to the ground. The time going up is equal to the time going down, so we can use this time to solve for the intial scenario of going up.

vf_y=vi_y+at

Remember that going up the vertical final velocity is 0m/s, and remember that gravity is always moving downwards so it is negative.

0m/s=vi_y+-9.8m/s^{2}(0.782s)\\-vi_y=-9.8m/s^{2}(0.782s)\\-vi_y=-7.66m/s\\vi_y=7.66m/s

So we have our first initial vertical velocity:

Viy = 7.66m/s

Next we solve for the horizontal velocity. We use the same kinematic formula but replace it with x components. Remember that gravity has no influence horizontally so a = 0:

d_x=V_i_xt+\dfrac{1}{2}0m/s^{2}(t^{2})\\d_x=V_i_xt

But horizontally, it considers the time of flight, from the time it was released and the time it hits the ground. Also, like mentioned earlier the time going up is the same as going down, so if we combine them the total time in flight will be twice the time.

T= 2t

T = 2 (0.782s)

<em>T = 1.564s</em>

<em>So we use this in our formula:</em>

<em>d_x=V_i_xT\\\\10.0m=Vi_x(1.564s)\\\\\dfrac{10.0m}{1.564s}=V_i_x\\\\6.39m/s=V_i_x</em>

Vix=6.39m/s

Now we have the horizontal and the vertical component, we can solve for the diagonal initial velocity, or the velocity the mountain lion leapt and the angle, by creating a right triangles, using vectors (see attached)

To get the diagonal, you just use the Pythagorean theorem:

c²=a²+b²

Using it in the context of our problem:

Vi^{2}=Viy^2+Vix^2\\Vi^2=(7.66m/s)^2+(6.39m/s)^2\\\sqrt{Vi}=\sqrt{(7.66m/s)^2+(6.39m/s)^2}\\\\Vi=9.98m/s

The lion leapt at 9.98m/s

Using SOHCAHTOA, we know that we can TOA to solve for the angle, because we have the opposite and adjacent side:

Tan\theta=\dfrac{O}{A}\\\\Tan\theta=\dfrac{V_i_y}{V_i_x}\\\\\theta=Tan^{-1}\dfrac{V_i_y}{V_i_x}\\\\\theta=Tan^{-1}\dfrac{7.66m/s}{6.39m/s}\\\\\theta=50.17

The lion leapt at an angle of 50.16°.

6 0
3 years ago
Visible electrical discharge from a storm cloud is called?
SOVA2 [1]

id have to say its thunder

7 0
3 years ago
Parasaurolophus was a dinosaur whose distinguishing feature was a hollow crest on the head. The 1.5-m-long hollow tube in the cr
Oksi-84 [34.3K]

Answer:

f1 = 58.3Hz, f2 = 175Hz, f3 = 291.6Hz

Explanation:

lets assume speed of sound is 350 m/s.

frequencies of a standing wave modes of an open-close tube of length L

fm = m(v/4L)

where m is 1,3,5,7......

and fm = mf1

where f1 = fundamental frequency

so therefore: f1 = 350 x 4 / 1.5

f1 = 58.3Hz

f2 = 3 x 58.3

f2 = 175Hz

f3 = 5 x 58.3

f3 = 291.6Hz

5 0
4 years ago
Other questions:
  • If two objects collid and one is initially at rest, is it possible for both to be at rest after the collision?
    8·1 answer
  • It takes a car 2 minute(s) to go from rest to 25 m/s east. What is the acceleration
    14·1 answer
  • The magnetic flux through a coil of wire containing two loops changes at a constant rate from -83 Wb to 82 Wb in 0.39 s .
    15·1 answer
  • Please Help ASAP
    14·1 answer
  • If the actual mechanical advantage of a machine is 4.2, and the input force is 10.0 N, what is the output force?
    6·1 answer
  • An airplane flies 40km directly south in 10 minutes and 20 km directly east in five minutes, its average speed is:
    11·2 answers
  • A copper plate is free to swing between the poles of a large electromagnet. When the field is turned up the plate Group of answe
    12·1 answer
  • How might the temperatures on Mercury be different if it had the same mass as Earth?
    7·1 answer
  • BERE
    7·2 answers
  • What are the units for specific charge?<br> A. C/kg<br> B. C*kg<br> C. kg/C<br> D. 1/C*kg
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!