Physics 263: Practice for Midterm
1. (Literally a GRE question—choose a letter, but also add a word or two of explanation.)
In an inertial frame S, two events occur on the xaxis seperated in time by Δ
t
and in
space by Δ
x
. In another inertial frame
S
0
, moving in the xdirection relative to S,
the two events could occur at the same time under which, if any, of the following
conditions?
(a) For any values of Δ
x
and Δ
t
(b) Only if

Δ
x/
Δ
t

< c
(c) Only if

Δ
x/
Δ
t

> c
(d) Only if

Δ
x/
Δ
t

=
c
(e) Under no condition
2. A particle of rest mass
m
has total energy
E
as it travels down the
x
axis. It decays
in to a pair of photons, one of which continues down the +
x
axis, while the other goes
in the opposite (

x
) direction.
(a) Find the energies
E
1
and
E
2
of the photons.
(b) If we trade the input parameter
E
for the particle’s velocity
v
, ﬁnd the series
expansion for
E
1
and
E
2
to
linear
order in
v/c
, i.e. dropping order
v
2
/c
2
.
3. Consider the familiar situation: Alan stands on the ground while Beth is at middle of
This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
This is the end of the preview.
Sign up
to
access the rest of the document.
 Spring '10
 Kilcup
 Inertia, Special Relativity, Beth

Click to edit the document details