Week 12 Homework Assignment
- An oil drop whose mass is determined to be 2.8 x 10-15kg is
held at rest between two large plates separated by 1.0cm when the potential
difference between them is 340V. How many excess electrons does this drop
have?
- The steps of a flight of stairs are 20.0cm high (vertically). If a 58.0-kg
person stands with both feet on the same step, what is the gravitational
potential energy of this person, relative to the ground, on (a) the
first step, (b) the second, (c) the third step, (d) the nth
step? (e) What is the change in energy as the person descends from step
6 to step 2?
- In a photoelectric effect experiment it is observed that no current flows
unless the wavelength is less than 570nm. (a) What is the work function
of this material? (b) What is the stopping voltage required if light of
wavelength 400nm is used?
- What is the longest wavelength photo that could produce a
proto-antiproton pair? (Each has a mass of 1.67 x 10-27kg.)
- What is the wavelength of an electron of energy 10eV?