Which is an example of a chemical change?

UV radiaGon having a wavelength of 120 nm falls on gold metal, to which electrons are bound by 4.82 eV. What is the maximum kine

Solnce55 [7]

Answer:

K.E = 5.53 eV = 8.85 x 10⁻¹⁹ J

Explanation:

First we calculate the energy of photon:

E = hc/λ

where,

E = Energy of Photon = ?

h = Plank's Constant = 6.626 x 10⁻³⁴ J.s

c = speed of light = 3 x 10⁸ m/s

λ = wavelength = 120 nm = 1.2 x 10⁻⁷ m

Therefore,

E = (6.626 x 10⁻³⁴ J.s)(3 x 10⁸ m/s)/(1.2 x 10⁻⁷ m)

E = (16.565 x 10⁻¹⁹ J)(1 eV/1.6 x 10⁻¹⁹ J)

E = 10.35 eV

Now, from Einstein's Photoelectric equation we know that:

Energy of Photon = Work Function + K.E of Electron

10.35 eV = 4.82 eV + K.E

K.E = 10.35 eV - 4.82 eV

4 0

2 years ago

If the moment acting on the cross section is M=630N⋅m, determine the maximum bending stress in the beam. Express your answer to

-BARSIC- [3]

Answer:

2.17 Mpa

Explanation:

The location of neutral axis from the top will be

$\bar y=\frac {(240\times 25)\times \frac {25}{2}+2\times (20\times 150)\times (25+(\frac {150}{2}))}{(240\times 25)+2\times (20\times 150)}=56.25 mm$

Moment of inertia from neutral axis will be given by $\frac {bd^{3}}{12}+ ay^{2}$

Therefore, moment of inertia will be

$\frac {240\times 25^{3}}{12}+(240\times 25)\times (56.25-25/2)^{2}+2\times [\frac {20\times 150^{3}}{12}+(20\times 150)\times ((25+150/2)-56.25)^{2}]=34.5313\times 10^{6} mm^{4}}$

Bending stress at top= $\frac {630\times 10^{3}\times (175-56.25)}{34.5313\times 10^{6}}=2.1665127\approx 2.17 Mpa$

Bending stress at bottom= $\frac {630\times 10^{3}\times 56.25}{34.5313\times 10^{6}}=1.026242858\approx 1.03$ Mpa

Comparing the two stresses, the maximum stress occurs at the bottom and is 2.17 Mpa

8 0

3 years ago

PLEASE HELP ASAP

morpeh [17]

A is the correct answer

7 0

3 years ago

Can you have zero displacement and nonzero average velocity? Zero displacement and nonzero velocity? Illustrate your answers on

Svetlanka [38]

a) Not possible

b) Yes, it's possible (see graph in attachment)

Explanation:

a)

The average velocity of a body is defined as the ratio between the displacement and the time elapsed:

$v=\frac{\Delta x}{\Delta t}$

where

$\Delta x$ is the displacement

$\Delta t$ is the time elapsed

In this problem, we want to have zero displacement and non-zero average velocity. From the equation above, we see that this is not possible. In fact, if the total displacement is zero,

$\Delta x = 0$

And therefore as a consequence,

$v=0$

which means that the average velocity is zero.

B)

Here we want to have zero displacement and non-zero velocity. In this case, it is possible: in fact, we are not talking about average velocity, but we are talking about (instantaneous) velocity.

On a position-time graph, the instantaneous velocity is the slope of the graph. Look at the graph in attachment. We see that the position of the object first increases towards positive value, then it decreases (the object starts moving backward), then becomes negative, then it increases again until returning to the original position, x = 0.

In all of this, we notice that the total displacement of the object is zero:

$\Delta x = 0$

However, we notice that the instantaneous velocity of the object at the various instants is not zero, because the slope of the graph is not zero.

Learn more about average velocity:

brainly.com/question/8893949

brainly.com/question/5063905

#LearnwithBrainly

3 0

3 years ago

What happens at the end of silence of the lambs?

sukhopar [10]

The Silence of the Lambs ends when Hannibal Lecter, from a payphone in the tropics, congratulates FBI Academy graduate Clarice Starling and gently warns her not to hunt him, ending the call by saying he had to go because he was having a friend for dinner, as he watched his hospital tormenter, Dr. Chilton, disembark from a plane. While that nervous laugh allowed movie goers to summon the courage to leave the theater and run to their cars, the original ending scripted by Tally gave no such quarter. When Lecter speaks to Starling, he compliments her outfit, which makes her realize he had watched from a distance. In the original ending, Lecter is cutting orange segments with a small paring knife, while he speaks to Clarice. As he hangs up the phone, the camera shot widens. We discover that he”s at a desk in a book lined office. There is the body of a bodyguard on the floor, and then we see Lecter is not alone. Chilton is trussed up in a chair across from him, the same method of restraints the doctor used on Lecter earlier in the movie. Lecter rises, slowly, a dreamy gleam in his eye, as he approaches his terrified victim, paring knife in hand. “Shall we begin?”

3 0

3 years ago