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3 years ago

A machine that promises more energy output than input is??

1 answer:

3 0

-- sometimes presented as a "perpetual motion machine" /// -- impossible to construct /// -- a scam /// -- a fraud /// -- often lubricated with snake oil

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A tube with a cap on one end, but open at the other end, has a fundamental frequency of 130.8 Hz. The speed of sound is 343 m/s

sergey [27]

Answer:

Y = V / f where Y equals wavelength

4 Y1 = V / f1 for a closed pipe the wavelength is 1/4 the length of the pipe

2 Y2 = V / f2 for the open pipe the wavelength is 1/2 the length of the pipe

Y1 / Y2 = 2 = f2 / f1 dividing equations

f2 = 2 f1

the new fundamental frequency is 2 * 130.8 = 261.6

(The new wavelength is 1/2 the original wavelength so the frequency must double to produce the same speed.

8 0

3 years ago

The force on an object is F⃗ =−17j⃗ . For the vector v⃗ =2i⃗ +3j⃗ , find: (a) The component of F⃗ parallel to v⃗

Igoryamba

Answer:

(a) $\vec F_{\parallel} = -\frac{102}{13}\,i-\frac{103}{13}\,j$ , (b) $\vec F_{\perp} = \frac{102}{13}\,i -\frac{68}{13}\,j$ , (c) $W = -51$

Explanation:

The statement is incomplete:

The force on an object is $\vec F = -17\,j$ . For the vector $\vec v = 2\,i +3\,j$ . Find: (a) The component of $\vec F$ parallel to $\vec v$ , (b) The component of $\vec F$ perpendicular to $\vec v$ , and (c) The work $W$ , done by force $\vec F$ through displacement $\vec v$ .

(a) The component of $\vec F$ parallel to $\vec v$ is determined by the following expression:

$\vec F_{\parallel} = (\vec F \bullet \hat {v} )\cdot \hat{v}$

Where $\hat{v}$ is the unit vector of $\vec v$ , which is determined by the following expression:

$\hat{v} = \frac{\vec v}{\|\vec v \|}$

Where $\|\vec v\|$ is the norm of $\vec v$ , whose value can be found by Pythagorean Theorem.

Then, if $\vec F = -17\,j$ and $\vec v = 2\,i +3\,j$ , then:

$\|\vec v\| =\sqrt{2^{2}+3^{3}}$

$\|\vec v\|=\sqrt{13}$

$\hat{v} = \frac{1}{\sqrt{13}} \cdot(2\,i + 3\,j)$

$\hat{v} = \frac{2}{\sqrt{13}}\,i+ \frac{3}{\sqrt{13}}\,j$

$\vec F \bullet \hat{v} = (0)\cdot \left(\frac{2}{\sqrt{13}} \right)+(-17)\cdot \left(\frac{3}{\sqrt{13}} \right)$

$\vec F \bullet \hat{v} = -\frac{51}{\sqrt{13}}$

$\vec F_{\parallel} = \left(-\frac{51}{\sqrt{13}} \right)\cdot \left(\frac{2}{\sqrt{13}}\,i+\frac{3}{\sqrt{13}}\,j \right)$

$\vec F_{\parallel} = -\frac{102}{13}\,i-\frac{153}{13}\,j$

(b) Parallel and perpendicular components are orthogonal to each other and the perpendicular component can be found by using the following vectorial subtraction:

$\vec F_{\perp} = \vec F - \vec F_{\parallel}$

Given that $\vec F = -17\,j$ and $\vec F_{\parallel} = -\frac{102}{13}\,i-\frac{153}{13}\,j$ , the component of $\vec F$ perpendicular to $\vec v$ is:

$\vec F_{\perp} = -17\,j -\left(-\frac{102}{13}\,i-\frac{153}{13}\,j \right)$

$\vec F_{\perp} = \frac{102}{13}\,i + \left(\frac{153}{13}-17 \right)\,j$

$\vec F_{\perp} = \frac{102}{13}\,i -\frac{68}{13}\,j$

(c) The work done by $\vec F$ through displacement $\vec v$ is:

$W = \vec F \bullet \vec v$

$W = (0)\cdot (2)+(-17)\cdot (3)$

$W = -51$

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3 years ago

HELP ASAPP!!!! WILL GIVE BRAINLIEST!<br> Describe the chemical structure of a cell membrane

Masja [62]

Answer:

Explanation:

The plasma membrane is composed of a bilayer of phospholipids, with their hydrophobic, fatty acid tails in contact with each other. ... Carbohydrates are attached to some of the proteins and lipids on the outward-facing surface of the membrane. These form complexes that function to identify the cell to other cells.

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3 years ago

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Báo cáo thực hành

pishuonlain [190]

Answer:

which language is this

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3 years ago

What is electron affinity?

Andrews [41]

Answer:

The electron affinity of an atom or molecule is defined as the amount of energy released when an electron is attached to a neutral atom or molecule in the gaseous state to form a negative ion.

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3 years ago