Photons with 605 THz frequency strike metal of 1.2eV work function. Calculate the maximum energy of photoelectrons and their velocity. What amount of energy is necessary to stop all photoelectrons? (Planck's constant. electron mass and charge are given)

Start off by converting all given data into SI units to avoid confusion later on. The photoelectric effect happens when photons with energy larger than work function strike metal, thus releasing the electrons from it. Write down the formula for photoelectric effect and check if all terms are understood: KE = E(photons) - W = hf - W (W- work function, KE- kinetic energy, f- frequency of photons). Put in the values to find kinetic energy: KE = 2.0810^-19 J. For velocity just adjust the kinetic energy formula from KE=(mv^2)/2 to v=(2KE/m)^1/2. Plug in the values and find the velocity v = 675752.2 m/s. As for the last part, it is enough to use the same amount as maximum kinetic energy to completely stop all photoelectrons. The stopping energy must be higher or equivalent to the photoelectron energy.

IV
Answered by Ignas V. Physics tutor

2262 Views

See similar Physics GCSE tutors

Related Physics GCSE answers

All answers ▸

Why do you weigh less on the Moon than on Earth?


What is red shift?


Why do astronauts feel weightless while in orbit?


Two balls of identical size and shape are dropped from the same height. One ball has a mass of 50kg and the other has a mass of only 10kg. Why do they reach the ground at the same time?


We're here to help

contact us iconContact ustelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

© MyTutorWeb Ltd 2013–2025

Terms & Conditions|Privacy Policy
Cookie Preferences