ConcepTest 8.3 Up the Hill
Two paths lead to the top of a big hill. One is steep and direct, while the other is twice as long but less steep. How much more potential energy would you gain if you take
PHY 53
Summer 2010
Assignment 10
1.
Two identical point masses, each of mass m, are attached
by a massless horizontal rod of length as shown. They
are rotating at angular velocity about a xed axle
per
PHY 53
Summer 2010
Assignment 9
1.
A heavy cylindrical container is being rolled up an
incline as shown, by applying a force parallel to the
incline. The static friction coefcient is s . The
cylinder
PHY 53 Summer 2010
Duke Marine Laboratory
1.
Some questions about the vector product C = A B .
a.
Assignment 8
Prove the rules given in the notes for the magnitude and direction of C
from the denition
PHY 53
Summer 2010
Assignment 7
Reading: Systems of Particles
Key concepts: Center of mass, momentum, motion relative to CM, collisions.
1.
Two identical balls of mass m are
propelled at t = 0 from th
PHY 53
Summer 2010
Assignment 6
Reading: Energy 2
Key Concepts: Potential energy, total energy, conservation of mechanical energy,
equilibrium and turning points.
1.
Some statements about the law of c
PHY 53
Summer 2010
Assignment 5
Reading: Energy 1
Key Concepts: Scalar products, work, kinetic energy, work-energy theorem.
1.
Questions about the scalar product of two vectors.
a.
Use vectors to prov
PHY 53
Summer 2010
Assignment 4
Reading: Dynamics 2
Key concepts: Radial forces, effective gravity.
1.
A block of mass m slides at constant speed down an incline of angle .
a.
What is the coefcient of
PHY 53
Summer 2010
1.
Three systems in static equilibrium.
a.
Assignment 11
A mobile hangs as shown.
The strings and crossbars are
massless. The strings supporting
the crossbars are attached at
distan
PHY 53
Summer 2010
1.
The king ordered a crown of solid pure gold, but what he got didnt feel right, so
he asked Archimedes to verify that it was really solid and all gold. Archimedes
realized he need
Physics 53
Dynamics 2
For every complex problem there is one solution that is simple, neat and wrong.
H.L. Mencken
Force laws for macroscopic objects
Newtons program mandates studying nature in order
Physics 53
Dynamics 1
. from the same principles, I now demonstrate the frame of the System of the World.
Isaac Newton, Principia
Reference frames
When we say that a particle moves in a certain way,
PHY 53
Summer 2010
Assignment 18
1.
For each of the cycles in Probs. 1-3 of Assignment 17, do the following.
a.
b.
Find the total work done and the efciency of an engine running on that
cycle.
c.
2.
F
PHY 53
Summer 2010
Assignment 17
1.
We take the expansion steps in the last problem of Assignment 16 and add steps
to make a cycle. The rst step starts with one mole of an ideal gas at pressure P0
and
PHY 53
Summer 2010
Assignment 16
1.
Some questions about air.
a.
b.
Explain the afternoon sea breeze.
c.
Explain why an air bubble in water grows in volume as it rises.
d.
2.
Explain why warm air rise
PHY 53
Summer 2010
Assignment 15
1.
Take the usual reference intensity for the db scale for sound, I0 = 1012 W/m 2 .
a.
b.
2.
What is the intensity of a sound of loudness 120 db?
If this is the intens
PHY 53
Summer 2010
Assignment 14
1.
A harmonic wave in a string is described by y( x , t ) = 0.01 cos(0.6 x 60 t ) . [SI
units.]
a.
b.
What is the frequency f?
c.
What is the speed v of the wave?
d.
2
Supplementary Problems for Topics III
PHY 53 Summer 2010
1.
1.
Duke Marine Laboratory
An empty steel drum of mass M, height h and cross-section area A is floating
n in water. T 13
partially submerged
PHY 53
Summer 2010
Assignment 3
Reading: Dynamics 1
Key concepts: Reference frames, inertia, mass, force, Newtons laws of motion, friction.
1.
A skilled oarsman rows his boat back and forth across a r
PHY 53
Summer 2010
Assignment 2
Reading: Kinematics 2
Key Concepts: Projectiles; circular motion.
[In problems with numbers, use g = 10 m/s2 .]
1.
Ball A and ball B are thrown with the same vertical c
Exam Taking Hints
Make sure that you budget your time wisely. If it is a 75 minute exam, a useful time allocation may be as follows: Spend 10-15 minutes combined on all multiple choice questions; Use
Problem Set 3 Solutions (Giancoli 4th ed.)
19. (a) Consider the free-body diagram for the crate on the surface. There is no motion in the y direction and thus no acceleration in the y direction. Write