Which two ways dose inertia affect the monitors of the planets

The following table lists the work functions of a few common metals, measured in electron volts. Metal Φ(eV) Cesium 1.9 Potassiu

Citrus2011 [14]

A. Lithium

The equation for the photoelectric effect is:

$E=\phi + K$

where

$E=\frac{hc}{\lambda}$ is the energy of the incident light, with h being the Planck constant, c being the speed of light, and $\lambda$ being the wavelength

$\phi$ is the work function of the metal (the minimum energy needed to extract one photoelectron from the surface of the metal)

K is the maximum kinetic energy of the photoelectron

In this problem, we have

$\lambda=190 nm=1.9\cdot 10^{-7}m$ , so the energy of the incident light is

$E=\frac{hc}{\lambda}=\frac{(6.63\cdot 10^{-34}Js)(3\cdot 10^8 m/s)}{1.9\cdot 10^{-7} m}=1.05\cdot 10^{-18}J$

Converting in electronvolts,

$E=\frac{1.05\cdot 10^{-18}J}{1.6\cdot 10^{-19} J/eV}=6.5 eV$

Since the electrons are emitted from the surface with a maximum kinetic energy of

K = 4.0 eV

The work function of this metal is

$\phi = E-K=6.5 eV-4.0 eV=2.5 eV$

So, the metal is Lithium.

B. cesium, potassium, sodium

The wavelength of green light is

$\lambda=510 nm=5.1\cdot 10^{-7} m$

So its energy is

$E=\frac{hc}{\lambda}=\frac{(6.63\cdot 10^{-34}Js)(3\cdot 10^8 m/s)}{5.1\cdot 10^{-7} m}=3.9\cdot 10^{-19}J$

Converting in electronvolts,

$E=\frac{3.9\cdot 10^{-19}J}{1.6\cdot 10^{-19} J/eV}=2.4 eV$

So, all the metals that have work function smaller than this value will be able to emit photoelectrons, so:

Cesium

Potassium

Sodium

C. 4.9 eV

In this case, we have

- Copper work function: $\phi = 4.5 eV$

- Maximum kinetic energy of the emitted electrons: K = 2.7 eV

So, the energy of the incident light is

$E=\phi+K=4.5 eV+2.7 eV=7.2 eV$

Then the copper is replaced with sodium, which has work function of

$\phi = 2.3 eV$

So, if the same light shine on sodium, then the maximum kinetic energy of the emitted electrons will be

$K=E-\phi = 7.2 eV-2.3 eV=4.9 eV$

7 0

3 years ago

A horizontal line on a displacement-time graph means the object is

r-ruslan [8.4K]

Answer:

traveling further away

Explanation:

4 0

3 years ago

Describe mechanical energy in your own words

Vlad [161]

Answer:

motion......

movement.....

3 0

3 years ago

Read 2 more answers

What can destroy stuff yet does not have any mass

Artist 52 [7]

If energy could be created or destroyed, all of our ideas of how the world works ... Historically, of course not all the forms of energy were known to begin with. ... too messy or complicated to make sense, we would have had to give up the law. ... can be converted into rest mass and back again (particle physicists do this every )

3 0

3 years ago

Who developed a unit of electric potential and electromotive force

ehidna [41]

Answer:

Alessandro Volta

Explanation:

Alessandro Volta composed a letter to his amigo, Sir Joseph Banks at the Royal Society of London, in March 1800. In it, Volta drew an image of his voltaic heap, an exacting heap of 24 copper and zinc plates, in addition to cardboard circles absorbed salt. Volta at that point associated copper wires to both the top and base to utilize it as power source.
The voltaic heap and wires would at that point, in principle, charge something helpful, similar to a light or a little engine, however since neither existed in 1800, Volta put the two wires on the tip of his tongue. His tongue, wet with salivation, was a decent conductor and finished the circuit. Volta gave himself a decent stun, accordingly demonstrating he had made another sort of battery, or electrochemical vitality source.
While researchers presently don't prescribe putting live wires on your tongue, Volta was respected for his commitments to science and we named the volt (V), or the unit of measure for electric potential, in his respect.

4 0

3 years ago