PHY 242
Lab 2: Function Generator and Oscilloscope.
Introduction
Last lab we introduced the ideas of Voltage, Current, and Resistance. This week we will explore
these ideas again, however these quantities will be changing in time. One way to make things
c
Example 1:
A child of mass m slides down a helter
skelter of height, h. Assuming the
slide is frictionless, what is the speed of
the child at the bottom of the slide ?
h=10m
From the CONSERVATI ON OF MECHANICAL ENERGY,
Emec ,i Emec , f U i K i U f K f
1 2
Physics 232: Worksheet 2
September 1, 2016
Please show all the intermediate steps for your benefit.
1. Probelm 1
A small plastic ball with mass m is suspended by a string with length L in a
uniform electric field E as shown in Figure. The ball is in equil
Physics 232 : Formula sheet for Midterm 1
1. Coulombs law :
q1 q2
~ 12 ,
F~12 = ke 2 r12 = q2 E
r12
where F~ , ke , q1 , q2 , ~r12 are the force, ke =
2
with the 0 = 8.85 1012 NCm2 as the permittivity of
~ 12 is the electric field sue
the free space, char
Physics 232
Electricity, Magnetism & Physical Optics
Class Schedule (subject to change)
Month
Aug
Aug
Aug
Aug
Aug
Sep
Sep
Sep
Sep
Sep
Sep
Sep
Sep
Sep
Sep
Sep
Sep
Sep
Sep
Sep
Sep
Sep
Sep
Oct
Oct
Oct
Oct
Oct
Oct
Oct
Oct
Oct
Oct
Oct
Oct
Oct
Oct
Oct
Oct
Oct
N
Physics 232: Solutions for Worksheet 4
September 15, 2016
Please show all the intermediate steps for your benefit.
1. Problem 1
Find the potential at point X, a distance R from a point charge +Q.
Sol: The potential is V = ke Q
R.
2. Problem 2
Distribute t
Physics 232: Vector Calculus Review
August 25, 2016
Please show all the intermediate steps for your benefit.
Tom and Jane are both trying to get to the soda machine on the 2nd floor from the
doorway of a room on the 1st floor. They decide to take differen
Physics 232: Worksheet 4
September 15, 2016
Please show all the intermediate steps for your benefit.
1. Problem 1
Find the potential at point X, a distance R from a point charge +Q.
2. Problem 2
Distribute the charge +Q uniformly over an arc length of rad
Work Done by an External Force
Previously we have looked at the work done to/from an object.
We can extend this to a system of more than one object.
Work is the energy transferred to or from a system by means of an
external force acting on that system.
No
The Potential Energy Curve
For the 1 - D case, the work done, W , by a force, F , moving an
object thr ough a displacement, x equals, Fx , therefore , the
potential energy can be written as
U x
dU x
U x W Fx F
x
dx
e.g ., Hooke' s Law, if the elastic p
Equilibrium Points
Equilibrium Points: refer to points where, dU/dx=-F(x)=0.
Neutral Equilibrium: is when a particles total mechanical energy is
equal to its potential energy (i.e., kinetic energy equals zero). If no
force acts on the particle, then dU/dx
Determining
Potential
Energy
Values
x
x
W F ( x)dx , U F ( x)dx . For GRAVIT. POT. ENERGY,
f
f
xi
xi
yf
yf
yi
yi
yf
U F ( y )dy mg dy mg dy mg y f yi
yi
U grav mg y f yi mgy
Only CHANGES in gravitatio nal Pot. energy are meaningful,
i.e., it is usual to d
8: Potential Energy & Conservation of Energy
POTENTIAL ENERGY (U) is the energy which can be associated with
configuration of a systems of objects. i.e. The position of an object
Also defined as the energy due to the position of the object
One example is
Conservation of Mechanical Energy
The mechanical energy is the sum of kinetic and potential energies,
Emech K U . If the system is isolated from its environmen t and
no external force causes any internal energy changes,
K W & U W , K U K f K i U f U i
K
Example 2:
A man of mass, m, jumps from a
ledge of height, h above the ground,
attached by a bungee cord of length
L. Assuming that the cord obeys
Hookes law and has a spring constant,
k, what is the general solution for the
maximum extension, x, of the c
Conservation of Energy
This states that
The total energy of a system, E, can only change by amounts of
energy that are transferred to or from the system.
Work done can be considered as energy transfer, so we can write,
W E Emec Eth Ein
Emec is the chang
Turning Points
For conservative forces, the
mechanical energy of the system
is conserved and given by,
U(x) + K(x) = Emec
where U(x) is the potential energy
and K(x) is the kinetic energy.
K 0 at ymax , Emec mgymax
F ( y )
Emec K ( y ) U ( y )
Therefore,
Guidelines and Information for writing Post-lab assignments for CHE 231
You will perform 5 experiments in this semester; for 2 (specified) of those 5 experiments you will
be submitting a Lab Report.
Each lab report wi