|
Standards that all students are expected to achieve in
the course of their studies are unmarked. Standards that all
students should have the opportunity to learn are marked
with an asterisk (*).
Motion and Forces
1. Newton's laws predict the motion of most objects. As a
basis for understanding this concept:
a. Students know how to solve problems
that involve constant speed and average speed.
b. Students know that when forces are balanced,
no acceleration occurs; thus an object continues to move
at a constant speed or stays at rest (Newton's first
law).
c. Students know how to apply the law F
= ma to solve one-dimensional motion problems
that involve constant forces (Newton's second law).
d. Students know that when one object exerts a
force on a second object, the second object always exerts
a force of equal magnitude and in the opposite direction
(Newton's third law).
e. Students know the relationship between the
universal law of gravitation and the effect of gravity on
an object at the surface of Earth.
f. Students know applying a force to an object
perpendicular to the direction of its motion causes the
object to change direction but not speed (e.g., Earth's
gravitational force causes a satellite in a circular
orbit to change direction but not speed).
g. Students know circular motion requires the
application of a constant force directed toward the
center of the circle.
h.* Students know Newton's laws are not exact
but provide very good approximations unless an object is
moving close to the speed of light or is small enough
that quantum effects are important.
i.* Students know how to solve two-dimensional
trajectory problems.
j.* Students know how to resolve
two-dimensional vectors into their components and
calculate the magnitude and direction of a vector from
its components.
k.* Students know how to solve two-dimensional
problems involving balanced forces (statics).
l.* Students know how to solve problems in
circular motion by using the formula for centripetal
acceleration in the following form: a =
v2/r.
m.* Students know how to solve problems
involving the forces between two electric charges at a
distance (Coulomb's law) or the forces between two masses
at a distance (universal gravitation).
Conservation of Energy and Momentum
2. The laws of conservation of energy and momentum
provide a way to predict and describe the movement of
objects. As a basis for understanding this concept:
a. Students know how to calculate kinetic
energy by using the formula E =
(1/2)mv2.
b. Students know how to calculate changes in
gravitational potential energy near Earth by using the
formula (change in potential energy) = mgh
(h is the change in the elevation).
c. Students know how to solve problems
involving conservation of energy in simple systems, such
as falling objects.
d. Students know how to calculate momentum as
the product mv.
e. Students know momentum is a separately
conserved quantity different from energy.
f. Students know an unbalanced force on an
object produces a change in its momentum.
g. Students know how to solve problems
involving elastic and inelastic collisions in one
dimension by using the principles of conservation of
momentum and energy.
h.* Students know how to solve problems
involving conservation of energy in simple systems with
various sources of potential energy, such as capacitors
and springs.
Heat and Thermodynamics
3. Energy cannot be created or destroyed, although in
many processes energy is transferred to the environment as
heat. As a basis for understanding this concept:
a. Students know heat flow and work are
two forms of energy transfer between systems.
b. Students know that the work done by a heat
engine that is working in a cycle is the difference
between the heat flow into the engine at high temperature
and the heat flow out at a lower temperature (first law
of thermodynamics) and that this is an example of the law
of conservation of energy.
c. Students know the internal energy of an
object includes the energy of random motion of the
object's atoms and molecules, often referred to as
thermal energy. The greater the temperature of the
object, the greater the energy of motion of the atoms and
molecules that make up the object.
d. Students know that most processes tend to
decrease the order of a system over time and that energy
levels are eventually distributed uniformly.
e. Students know that entropy is a quantity
that measures the order or disorder of a system and that
this quantity is larger for a more disordered system.
f.* Students know the statement "Entropy tends
to increase" is a law of statistical probability that
governs all closed systems (second law of
thermodynamics).
g.* Students know how to solve problems
involving heat flow, work, and efficiency in a heat
engine and know that all real engines lose some heat to
their surroundings.
Waves
4. Waves have characteristic properties that do not
depend on the type of wave. As a basis for understanding
this concept:
a. Students know waves carry energy from
one place to another.
b. Students know how to identify transverse and
longitudinal waves in mechanical media, such as springs
and ropes, and on the earth (seismic waves).
c. Students know how to solve problems
involving wavelength, frequency, and wave speed.
d. Students know sound is a longitudinal wave
whose speed depends on the properties of the medium in
which it propagates.
e. Students know radio waves, light, and X-rays
are different wavelength bands in the spectrum of
electromagnetic waves whose speed in a vacuum is
approximately 3 x 108m/s (186,000
miles/second).
f. Students know how to identify the
characteristic properties of waves: interference (beats),
diffraction, refraction, Doppler effect, and
polarization.
Electric and Magnetic Phenomena
5. Electric and magnetic phenomena are related and have
many practical applications. As a basis for understanding
this concept:
a. Students know how to predict the
voltage or current in simple direct current (DC) electric
circuits constructed from batteries, wires, resistors,
and capacitors.
b. Students know how to solve problems
involving Ohm's law.
c. Students know any resistive element in a DC
circuit dissipates energy, which heats the resistor.
Students can calculate the power (rate of energy
dissipation) in any resistive circuit element by using
the formula Power = IR (potential difference) x
I (current) = 12R.
d. Students know the properties of transistors
and the role of transistors in electric circuits.
e. Students know charged particles are sources
of electric fields and are subject to the forces of the
electric fields from other charges.
f. Students know magnetic materials and
electric currents (moving electric charges) are sources
of magnetic fields and are subject to forces arising from
the magnetic fields of other sources.
g. Students know how to determine the direction
of a magnetic field produced by a current flowing in a
straight wire or in a coil.
h. Students know changing magnetic fields
produce electric fields, thereby inducing currents in
nearby conductors.
i. Students know plasmas, the fourth state of
matter, contain ions or free electrons or both and
conduct electricity.
j.* Students know electric and magnetic fields
contain energy and act as vector force fields.
k.* Students know the force on a charged
particle in an electric field is qE, where
E is the electric field at the position of the
particle and q is the charge of the particle.
l.* Students know how to calculate the electric
field resulting from a point charge.
m.* Students know static electric fields have
as their source some arrangement of electric charges.
n.* Students know the magnitude of the force on
a moving particle (with charge q) in a magnetic
field is qvB sin(a), where a is the
angle between v and B (v and B are
the magnitudes of vectors v and B,
respectively), and students use the right-hand rule
to find the direction of this force.
o.* Students know how to apply the concepts of
electrical and gravitational potential energy to solve
problems involving conservation of energy.
|