(separation of charge by rubbing)
1747(?) positive and negative, single fluid, all sorts of stuff!
1752 lightening is electrical discharge (lightening rod)
1753 Copely Medal, Royal Society ,MA Yale & Harvard
Atomic View of Thermal Energy and Temperature
The thermal energy of an
ideal gas is equal to the
total kinetic energy of the
moving atoms in the gas.
If we add heat to the gas, the
molecules will speed up and
the thermal energy will
In the ideal model, we only consider the force due to
gravity, so there is no acceleration in the direction.
In the direction, we have an acceleration due to gravity of
downward. For the following equations, we will use a
If we set up an orthogonal
system, we can express any
vector in terms of its
components along each of the
We can use trigonometry to find
the magnitudes of the
components. For a right triangle:
Just as velocity is the change in position with time,
acceleration is the change in velocity with time.
Instantaneous (change in velocity over a very short time interval)
Similarly, acceleration is the slope of the velocity vs. time graph.
PHY 2053 Section 802 TR 4- Mb) Exam #2 Form A
Name: u .3 March 8, 2016
1) A box, mass 35 kg, sits on a rough horizontal oor. The coefcient of static friction
between the box and the oor is 0.75. You apply a horizontal force of 150 N to the box. What
Uncertainty and Significant Figures
All measurements have some level of uncertainty.
We can express this uncertainty (or error) as a number plus/minus
For example, if the mass of a steel ball is given as , then the ball is
Conservation of Angular Momentum in Orbits
In a previous chapter, we discussed circular orbits and
In general, orbits are not circular, but elliptical.
In an elliptical orbit, is the speed constant?
Other important ideas, while practical, are not considered fundamental. They can be derived from
these, sometimes with the addition of empirical concepts (e.g. resistance).
Taken from Physics for Scientists and Engineers Second Edition: A strategic Approa
FIGURE 16.4 Phase diagrams (not to
scale) for water and carbon dioxide.
O 0.01 100 374
Solid and liquid Liquid and gas
are in phase are in phuse
p (atm) -
7 8 56 3 1
THERMAL PROPERTIES OF MATTER
Q18.1 The equation of state expressed in Eq.(18.1) shows that in general the volume V depends on
the temperature and pressure. An equation of state of this form applies only to a single phase of
Q22.1 The total flux through the balloon is q / 0 , regardless of the size of the balloon.
Q22.2 The flux through each surface is equal to
, where Qencl is the net charge enclosed by the
Lens sign convention
i is + if located in back of the lens
n = c/v
n1sin1 = n2sin2
o is + if located in front of the lens
f is + if lens is converging
1/i + 1/o = 1/f
Mirror sign convention
M= image height/object height
i is + if located in front of
Q32.1 Yes. The direction of the vector product E B can be determined and the wave is traveling
in this direction so must have come from the opposite direction.
Q32.2 Yes, there is no reason you cant ha
TEMPERATURE AND HEAT
Q17.1 To bring the thermometer to the same temperature as the water heat must flow from the water
into the thermometer material. If the thermometer is large compared to the amount of water, this heat
ELECTRIC CHARGE AND ELECTRIC FIELD
Q21.1 When a strip of tape is quickly peeled off the roll, electrons are transferred between the strip
and the rest of the roll. Therefore, the two strips have the same sign of net charge
THE FIRST LAW OF THERMODYNAMICS
Q19.1 (a) positive (volume of the gas increases) (b) positive (volume of the gas increases) (c)
negative (volume of the gas decreases) (d) negative (volume of the gas decreases).
Q19.2 Heat i
THE SECOND LAW OF THERMODYNAMICS
Q20.1 The cycle approaches reversibility as the temperature difference between the stove and water
approaches zero. In this limit an infinitesimal change in the temperature of the stove can
CAPACITANCE AND DIELECTRICS
Q24.1 E = V / d so for a given potential V across the capacitor E becomes larger as d is decreased.
When E exceeds the dielectric strength of whatever is between the plates of the capacitor, curr
Q23.1 The concept of potential is useful for the same reason that electric field is useful. It allows us
to calculate the effect of the source charges on the space surrounding them. A test charge then has
Example Questions for Exam #2
Note: These problems are provided as an example of the types of questions I might ask and the
level of understanding that I expect. This is in no way a comprehensive study guide. While th
Uniform Circular Motion
Constant magnitude; Pointing towards center
Time for one full circle
Circumference () divided by speed
Number of revolutions per second.
Circular Motion Example
a racecar going ar
Chapter 5 Outline
Applying Newtons Laws
When a body is not accelerating, we say that it is in
Statics is the stud
When forces pull on an object in
opposite directions, it is in
Youngs modulus, , describes
Tensile Stress Example
Chapter 9 Outline
Conservation of momentum