Question

Срочно!Какой частоты свет следует направить на поверхность платины, чтобы максимальная скорость фотоэлектронов стала 3000 км/с?Работа выхода для платины 6,3 эВ.

Answer 1

H*v=A+m*V^2/2
v=(A+m*V^2/2)/h=(6,3*10^-19+9*9*10^12/2)/6,63*10^-34=7,62*10^15 Гц

Answer 2

Calculation of the Frequency of Light

To determine the frequency of light required to achieve a maximum speed of 3000 km/s for photoelectrons on the surface of platinum, we can use the equation that relates the energy of a photon to its frequency:

E = hf

where: - E is the energy of the photon, - h is Planck's constant (approximately 6.626 x 10^-34 J·s), - f is the frequency of the light.

We can rearrange the equation to solve for the frequency:

f = E / h

To find the energy of the photons, we can use the work function of platinum, which is given as 6.3 eV (electron volts). We need to convert this energy to joules before using it in the equation. The conversion factor is 1 eV = 1.602 x 10^-19 J.

Converting the work function to joules:

6.3 eV * (1.602 x 10^-19 J/eV) = 1.00986 x 10^-18 J

Now we can substitute the energy into the equation to find the frequency:

f = (1.00986 x 10^-18 J) / (6.626 x 10^-34 J·s)

Calculating the frequency:

f = 1.00986 x 10^-18 J / 6.626 x 10^-34 J·s

f ≈ 1.526 x 10^15 Hz

Therefore, the frequency of light that needs to be directed onto the surface of platinum to achieve a maximum speed of 3000 km/s for photoelectrons is approximately 1.526 x 10^15 Hz.

Please note that the calculation assumes ideal conditions and does not take into account factors such as surface conditions, temperature, and other variables that may affect the actual outcome.