What is the effect on the force of gravity between two objects if the mass of one object doubles?

The following table lists the work functions of a few commonmetals, measured in electron volts.

steposvetlana [31]

Answer:

Lithium

Explanation:

The equation for the photoelectric effect is

$\frac{hc}{\lambda}= \phi + K_{max}$

where

$\frac{hc}{\lambda}$ is the energy of the incident photon, with

h being the Planck constant

c is the speed of light

$\lambda$ is the wavelength of the photon

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

$K_{max}$ is the maximum kinetic energy of the emitted photoelectrons

In this problem, we have

$\lambda= 190 nm = 1.9\cdot 10^{-7}m$ is the wavelength of the incident photon

$K_{max}=4.0 eV$ is the maximum kinetic energy of the electrons

First of all we can find the energy of the incident photon

$E=\frac{(6.63\cdot 10^{-34} Js)(3\cdot 10^8 m/s)}{1.90\cdot 10^{-7} m}=1.05\cdot 10^{-18} J$

Converting into electronvolts,

$E=\frac{1.05\cdot 10^{-18} J}{1.6\cdot 10^{-19} J/eV}=6.6 eV$

So now we can re-arrange the equation of the photoelectric effect to find the work function of the metal

$\phi = E-K_{max}=6.6 eV - 4.0 eV=2.6 eV$

So the metal is most likely Lithium, which has a work function of 2.5 eV.

3 0

2 years ago

A time-dependent but otherwise uniform magnetic field of magnitude B0(t) is confined in a cylindrical region of radius 6.5 cm. I

vodka [1.7K]

Answer:

a = 603.59 m/s^2

Explanation:

from the data given . the rate of change in magnetic field is as follow

$\frac{dB}{dt} = 280 G/s = 280 \times 10^{-4} T/s$

from the faraday's law of induction , the expression for the induced emf in region of radius r as follow

$\epsilon = \frac{d \phi}{dt}$

$\int E.dl = \frac{d(BA)}{dt}$

$E(2\pi r)= \pi r^2 \frac{dB}{dt}$

$E = \frac{r}{2} \frac{dB}{dt}$

electric field at point P_1 as follow

$E = \frac{r}{2} \frac{dB}{dt}$

$E = \frac{1.5\times 10^{-2}}{2} 280 \times 10^{-4}$

$E = 6.3\times 10^{-6} V/m$

from newton 2nd law of motion, the acceleration of proton is

F = ma

qE = ma

$a = \frac{qE}{m}$

$a = \frac{1.6 \times 10^{-19} (6.3\times 10^{-6})}{1.67\times 10^{-27}}$

a = 603.59 m/s^2

5 0

2 years ago

1. Why should you use scientific notation when writing big numbers?

Fynjy0 [20]

Answer:

It helps the answer look clean. It also makes the work easier to work with.

Explanation:

Instead of writing a lot of zeros, all you have to do is add exponents to the number to show how much the decimal moved.

6 0

2 years ago

When you cook a marshmallow on a metal poker tool over an open flame, energy is transferred. Identify the three different ways t

sergejj [24]

Answer:

The three ways thermal energy is transferred are;

1) Conduction

2) Convection

3) Radiation

Explanation:

1) The conduction of the heat from the open flame to the marshmallow is through the direct contact of the flame with the marshmallow, such that the flame the region of the combustion reaction, that produces light and heat touches the marshmallow

2) The convection process is the transfer of heat from the rising heated combustion products, as well as the heated air that rises from the flame

3) The radiation heat transfer is the transfer of the heat from the fire to the marshmallows directly by the heat the moves in the form of electromagnetic waves at temperatures above 1000 K, without the need for a medium, such that the marshmallow can be heated by the heat coming from side of the flame.

4 0

2 years ago

HELP I DONT HAVE MUCH TIME ILL time BRAINLIEST 10poINTSSSSSS HURYYYY

Soloha48 [4]

1.the sun must be lined up with the moon and earth all must be aligned for this to happen

6 0

2 years ago

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