Accelerated Physics-Chapter 1 Problem Set
Answer each of the following questions. Your answers need to be supported by work
and/or explanations as called for in order to earn full credit.
Use factor label
Section 6-6, 6-7, 6-8 Mechanical Energy and its Conservation
We can distinguish between the work done by conservative forces (not dependent of path
taken) and the work done by nonconservative (dependent on path taken) forces.
We find that the work done by
Can a force be exerted on an object and no work be done on the object?
Problems solving strategies for Work
1. Draw a free body diagram.
2. Choose a convenient coordinate system. (Usually it is convenient to choose the
direction of motion).
3. Apply Newto
Section 6-2 Work Done by Varying Force
The work done by a varying force can be determined graphically. If you plot F vs d, then the
work is the area under the curve at the two points.
The force on an object, acting along the x axis, varies as shown above.
mine (a) the
work done by each force acting on the crate, and (b) the net work done
(4) The work done on a backpack (a) Calculate the work a hiker must do on a backpack of
mass m = 15 kg in order to carry it up a hill of height h = 10 m, as sho
A dart of mass 0.100 kg is loaded in a toy dart gun. The spring in the gun has a spring constant
of 250 N/m. The spring is compressed 6.0 cm and then released. What speed does the dart
leave the gun with?
A 1.60 kg block slides with a speed of 0.950 m/s o
A ball of mass m = 2.60 kg, starting from rest, falls a vertical distance h = 55.0 cm before
striking a vertical coiled spring, which it compresses an amount Y = 15.0 cm. Determine the
spring constant. Assume the spring has negligible mass, and ignore air
b. How much energy did this require?
2. An elevator car of mass 1,600 kg, carries people, mass of 200 kg. A constant friction force of
4,000 N acts against the motion. Find the power needed for a motor to lift the car +
passengers at a constant velocity v
b. What was the net work done on the ball to make it reach this speed, starting from
(2) Calculate the net work required to accelerate a car, mass m = 1000-kg car from v1 = 20
m/s to v2 = 30 m/s.
(3) A car traveling at speed v1 = 60 km/h can brake t
Section 6-1 Work done by a constant force
Work what is accomplished when a force is applied to an object to move it over a distance
The work done on an object by a constant force (constant in both magnitude and direction) is
defined to be the product of t
. 1. A wave' 15 introduced into a medium
Wave Basics KEY Name: MW._._._._
Read from :iLesson 2 of the Waves chapter at The Physics Classroom:
http: IIwww. physicsclassroom com/C111sstavesIuIDIZahtml
http :./Iwww physicsclas sroom .comIC
. , . f i .
10. The period of a 261-Hertz sound wave is 2% Ian;-
7. Olive Udadi accompanies her father to the. park for an afternoon of fun. While ther. .7 . a *
swinIg and begins a motion characterized by a complete backand-forth c
The Quantum World
- the rest of the course.
Weve thought about fast things. Now I want to think
about small things.
In physics were used thinking of things like energy as
continuous. But some things are digitized, like
charge. 1e, 2e, 11e OK; 1.4e is not
Ive described an n-channel enhancement mode MOSFET,
since I enhance the minority concentration near OX when I
I can also build a p-channel depletion mode MOSFET.
- - trapped
The layer near OX
is already inverted
Ive mentioned the Shroedinger equation; now I need to
explain it, using energy conservation.
For simplicity let me assume I have a perfect travelling
= ei(kx - t)
If I want to measure energy, what can I do? Differentiate.
d/dt = -i ei(kx - t) = -i
Tunneling for E < U0
[ Does this mean you can magically throw a bowling ball
through the wall? ]
[ Ive drawn the same wavelength on either side. Is that right? ]
EX. L = 5 -1
Heres another way to think of the Compton wavelength.
What is the wavelength of a photon whose energy is
equal to the rest energy of a particle of mass m?
E = hc/ = mc2
= h/mc !
We studied the electron Compton wavelength (a couple
Energy Quantization in Atoms
Ill start with a planetary model, since that is what I was
told in grade school. And Ill start with hydrogen, the
Planck: Light is quantized, or
digitized, into chunks of nhf.
Bohr 1913: perha
Fri Sept. 6
Strange name: refers to physics 1900-1930!
Freshman or pre-med phys: Newton, Maxwell to
1900-1930: Newton/Maxwell usually OK, but only:
- slow stuff: v < c = 3 x 108 m/
Momentum. Since the time between two events
depends on the reference frame, you might suspect
that true momentum is not what you saw in freshman
physics. Einstein found the correct momentum is
p = mu
refers to a particle, not a
Ultimate Composition: What is everything made
Leptons such as the e- are elementary.
There are six leptons, plus their antiparticles.
These are not made of anything else.
m 200me , m 3500me. Otherwise quite similar.
Hadrons are made
Indeed, carbon-diamond is an insulator, and Si is a
semiconductor, as you know.
C = [He]2s22p2. You know the p-state has an
occupancy of 6.
In both C and Si, there are four valence electrons, as
The C or Si lattice with covalen