8.02x Problem Set 1 Solutions
Problem 1 (5 points)
a) The ratio of the electric force to the gravitational force for an electron
and a proton in a hydrogen atom is
Fe
Fg
=
=
ee
k r2
mm
G e2 p
r
=
k e2
=
G me mp
(1)
9.0 109 N m2 /C2
(1.6 1019 C)2
39
2 (9.1
8.02x Problem Set 11 Solutions
Problem 1 (10 points)
How to tell whether sound is an EM wave? Let us just list some of the
obvious dierences. Sound waves do not propagate in vacuum, they need some
medium (gas, solid, or liquid) to support them. The speeds
PROBLEM SET 10; 802x; SPRING 2005
1) The d ifferen tial equation governing an RLC cir cuit is:
-Ldi/d t - Ri + q/C = 0. Using i= - dq /dt, we hav e,
Ld2q/dt2 + Rdq/dt +q /C = 0.
The d ifferen tial equation governing a mass on a spring is (with v elo city
MIT Department of Physics
Physics 8.02X
Spring 2005
Solution to Problem Set #9
Problem 1 (20 points) The 1200 dipole magnets of the LHC accelerator at
CERN will have a field of 8 Tesla. Approximate the magnet as two square loops
of dimension 14m x 0.3 m,
8.02x Problem Set 8 Solutions
Problem 1 (10 points)
a) The currents run in the same direction x. The eld created by the rst
wire has direction z at the place of the second wire. The electrons in the
second wire move to x (opposite the current), so the Lor
MIT Department of Physics
Physics 8.02X
Spring 2005
Solution to Problem Set #2
Problem 1 (5 Points) Consider an infinite plane (non-conducting) with a uniform
negative surface charge density
(a) Draw a sketch of the electric field (using field lines) clo