In a photoelectric effect experiment you illuminate a metal with light of an unknown wavelength and measure the maximum kinetic energy of the photoelectrons to be 0.75 eV. Then you illuminate the same metal with light of a wavelength known to be 2/3 of the first wavelength and measure a maximum kinetic energy of 1.8 eV for the photoelectrons. Required:
a. Find the first wavelength, in nanometers
b. Find the metals work function, in electron volts

A.) 1658 nm

B.) 1.05 ev

Explanation:

Given that in a photoelectric effect experiment you illuminate a metal with light of an unknown wavelength and measure the maximum kinetic energy of the photoelectrons to be 0.75 eV. Then you illuminate the same metal with light of a wavelength known to be 2/3 of the first wavelength and measure a maximum kinetic energy of 1.8 eV for the photoelectrons.Required:

a. Find the first wavelength, in nanometers

The formula to use is:

E = hf

Where f = c/ wavelength.

C = speed of light.

Convert the electron volts to Joule.

0.75 × 1.6 × 10^-19 = 1.2 × 10^-19 J

Substitute the values into the formula

1.2 × 10^-19 = (6.63 × 10^-34 × 3 × 10^8) ÷ wavelength

Wavelength = (6.63×10^-34 × 3×10^8) ÷ 1.2×10^-19

Wavelength = 1.6575 × 10^-6 m

Therefore, the wavelength of the first light in nanometers will be

Wavelength = 1658 nm

b. Find the metals work function, in electron volts

The metal works function will be:

WF = 1.8 - 0.75 = 1.05 eV

a solenoid is created by wrapping a l = 90 m long wire around a hollow tube of diameter d = 4.5 cm.   the wire diameter is d = 0.9 mm.   the solenoid wire is then connected to a power supply so that a current of i = 9 a flows through the wire.

randomized variablesl = 90 m

d = 4.5 cm

d = 0.9 mm

i = 9 a                                          

write an expression for the number of turns, n, in the solenoid. you do not need to take into account the diameter of the wire in this calculation.

calculate the number of turns, n, in the solenoid.

write an expression for the length of the solenoid (l2) in terms of the diameter of the hollow tube d.

calculate the length of the solenoid (l2)   in meters.

calculate the magnitude of the magnetic field at the center of the solenoid in teslas.

explanation:

the bal will not change its velocity.