The force involved in beta decay that changes a proton to a neutron and releases an electron
and a neutrino.
Weber
The unit of magnetic flux, equal to one T · m^2.
Weight
The gravitational force exerted on a given mass.
Weightlessness
The experience of being in free fall. If you are in a satellite, elevator, or other free-falling object,
then you have a weight of zero Newtons relative to that object.
Work
Done when energy is transferred by a force. The work done by a force F in displacing an object
by s is W = F · s.
Work function
The amount of energy that metal must absorb before it can release a photoelectron from the
metal.
Work-energy theorem
States that the net work done on an object is equal to the object’s change in kinetic energy.
Z
Zeroth Law of Thermodynamics
If two systems, A and B, are in thermal equilibrium and if B and C are also in thermal
equilibrium, then systems A and C are necessarily in thermal equilibrium.
Practice Tests Are Your Best Friends
BELIEVE IT OR NOT, SAT II PHYSICS HAS some redeeming qualities. One of them is
reliability. The test doesn’t change much from year to year. While individual questions
will never repeat from test to test, the topics that are covered and the way in which they’re
covered will remain constant. This constancy can be of great benefit to you as you study
for the test.
Taking Advantage of the Test’s Regularity
Imagine an eleventh grader named Molly Bloom sits down at the desk in her room and
takes an SAT II Physics practice test. She’s a very bright young woman and gets only one
question wrong. Molly checks her answers and then jumps from her chair and does a
little dance that would be embarrassing if anyone else were around to see her.
After Molly’s understandable euphoria passes, she begins to wonder which question she
got wrong. She discovers that the question dealt with optics. Looking over the question,
Molly at first thinks the test writers made a mistake and that she was right, but then she
realizes that she answered the question wrong because she had assumed the focal point of
a diverging lens would have a positive value, when in fact it has a negative value. In
thinking about the question, Molly realizes she didn’t have a good grasp on which kinds
of mirrors and lenses have which kinds of focal points. She studies up on her optics, sorts
out why the focal point of a diverging lens must have a negative value, and memorizes