Experimental Question 2: An Optical "Black Box"
SOLUTION
a. Consider an incoming light beam at angle to the first mirror (see
figure). The angle to the second mirror is given by
.
Thus, the total deflection angle is
. In particular,
it is independent of .
Theoretical Question 3: Birthday Balloon
SOLUTION
a. Solution using forces:
Let the balloons radius be , and let be the pressure of the inside air. Consider the balloons rear half, and write
down the equilibrium of forces on it along the cylinders axis:
(
Theoretical Question 3: Birthday Balloon
The picture shows a long rubber balloon, the kind that is popular at birthday parties.
A partially inflated balloon usually splits into two domains of different radii. In this
question, we consider a simplified mod
Experimental Question 2: An Optical Black Box
TV and computer screens have advanced significantly in recent years. Today, most displays consist of a color LCD
filter matrix and a uniform white backlight source. In this experiment, we will study a sample o
Theoretical Question 2: Creaking Door
SOLUTION
a1. The motion here is pure sliding under a constant kinetic friction. This is harmonic motion with a displaced
equilibrium point. The angular frequency is given by:
From here, the period is:
The initial slop
Experimental Question 1: Levitation of Conductors in an Oscillating Magnetic Field
SOLUTION
a. Using Faradays law:
( )
(
)
The overall sign will not be graded.
For the current, we use the extensive hints in the question to write:
( )
(
)
(
)
This can be r
Theoretical Question 2: Creaking Door
The phenomenon of creaking is very common, and can be found in doors, closets, chalk squeaking on a blackboard,
playing a violin, new shoes, car brakes and other systems from everyday life. Here in Israel, a similar p
Theoretical Question 1: The Shockley-James Paradox
SOLUTION
a. The magnetic field created by the large loop at its center is:
Since
by:
, this is the field throughout the area of the small loop. Therefore, the flux through the small loop is given
The mutu
Experimental Question 1: Levitation of Conductors in an Oscillating Magnetic Field
In an oscillating magnetic field of sufficient strength, levitation of a metal conductor becomes possible. The levitation
occurs due to a non-zero mean magnetic force exert
Theoretical Question 1: The Shockley-James Paradox
In the year 1905, Albert Einstein proposed the special theory of relativity to resolve the inconsistency between
Newtons mechanics and Maxwells electromagnetism. Proper understanding of the theory led to