homework work mastering physics assignments study for exam rotational motion torque and angular...
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HomeworkHomework Work Mastering Physics Assignments Study for Exam
rotational motion torque and angular momentum static equilibrium gravity
Review Session - 7 PM - HL 188 Work Reading Assignment for Friday Work on Lab Presentation
ExampleExample A 150 kg satellite is in circular orbit of radius 7.3 Mm
about the earth. Determine the potential energy.
U = -8.2 x109 J Determine the orbital speed.
v = 7400 m/s Determine the kinetic energy.
K = 4.1x109 J What is the escape speed from
this altitude?
ExerciseExercise
Why are rocket launch sites located nearer to the equator (rather than the poles)?
Angular Momentum in the Bohr Model of the
Atom
Angular Momentum in the Bohr Model of the
Atom
In the Bohr model:
The electron orbits like a planet.
The electron can only have certain values of angular momentum.
L = n (h/2) where n is an integer
Angular Momentum in Quantum MechanicsAngular Momentum
in Quantum Mechanics
L = (h/2)gives length of angular momentum vector
Lz = ml (h/2)gives orientation of the angular momentum vector The Bohr quantum number
)1( ll
LLz
Quantum Numbers determine the shape of the state
Quantum Numbers determine the shape of the state
1s2s
2pl = 0 for s-state
l = 1 for p-state
l = 2 for d-state
LL = rr x mvv
Only s-states (L = 0) can have electrons at the origin.
More Static EqulibriumMore Static Equlibrium How does a truck scale work?
If the front wheels give a weight of 10000 N, the middle wheels (which are 3 m back) give a weight of 30000 N and the rear wheels (which are 10 m further back) give a weight of 25000 N, where is the center of mass of the truck?
Opening the paint can
Opening the paint can
A man tries to pry the lid off a can of paint with a very light screwdriver.
A force F is applied a distance L from the edge of the can. The screwdriver pushes up on the lid a distance d from edge of the can.
What is the upward force on the lid? What is the normal force supplied by edge of the can on
the screwdriver?
ExampleExample If the wall is
frictionless, the floor is not, what are the forces acting on the ladder?
FollowupFollowup
If the wall is frictionless, the coefficient of static friction between the ladder and the floor is 0.8, how large is the force of static friction?
ExampleExample
At what angle will the contents spill?
ExampleExample
A 9 m flagpole hangs in a horizontal position from the side of a building. It is supported by a hinge and a 15 m cable. Find the tension in the cable and the magnitude and direction of the force supplied by the hinge if the flagpole weighs 1500 N?