Download Spring Semester 2009

Los Altos Physics Spring Semester Final Exam Review
Mr. Randall
LAHS Physics - Spring Semester 2009
Final Exam Review Problems
The Spring semester final exam in physics includes material in studied during both first and
second semesters. Juniors and Seniors will take Finals on the same Senior final day:
6th period = Monday, June 1st
1st period = Tuesday, June 2nd .
The Final has TWO parts. You will have 75 minutes to complete the following:
50% Part I - Free Response (One of the 10 problems listed below chosen at random.)
50% Part II - 20 Multiple Choice (Similar to the practice and unit tests taken in class.)
Your Semester grade will be calculated as follows:
Quarter 3 grade => 40%
Quarter 4 grade => 40%
Semester 2 Final – Part I and II => 20%
Total Spring Semester Grade =>100%
Part I - 1 Free Response Questions to be completed individually
The Free Response problem on the exam will be graded with using partial credit. Generally,
points will be awarded for the following:
1. A clearly drawn sketch and labeled diagram modeling the problem including all initial conditions.
2. The concept formula in symbols used to solve the problem.
3. Logical, symbolic algebraic manipulations solving for the variable(s) in question.
4. The correct numerical value rounded to the correct significant figure + units of measure.
5. A box around the answer and a brief explanation of its meaning.
Part II - Multiple Choice Questions
The questions are mostly conceptual, some mathematical with the purpose of assessing how
well you understand the concepts discussed throughout the year – similar to the Practice
Multiple Choice questions distributed via the class website.
An equation sheet will be provided to remind you of the fundamental concepts and constants
from each unit.
1
Los Altos Physics Spring Semester Final Exam Review
Mr. Randall
1. Suppose you plugged into the wall outlet a configuration of electric appliances as represented by the
resistors in the circuit diagram shown below.
A. Find the equivalent total resistance of the circuit shown below.
15 Ω
10 V
30 Ω
6Ω
10 Ω
4Ω
20 Ω
40 Ω
B. In the circuit diagram above, draw in an ammeter to measure the current from the battery.
C. Determine what the ammeter would read for this circuit.
D. In the circuit diagram above, draw in a voltmeter to measure the voltage across the 15 Ω resistor.
Determine what the voltmeter would read for this circuit.
E. Determine the voltage across the 30 and 10 Ω resistors.
F. Determine the voltage across the combination of the 15, 20 and 40 Ω resistors.
G. Determine the current through the 40 Ω resistor.
H. How much power is dissipated by all the resistors in the circuit shown above?
I. How much power is supplied by the power source in the circuit shown above?
2.
Predict the mass of the Earth given that the Moon’s orbital radius is 3.84 x 108 meters and its orbital
period is 27.3 days.
+4q
3.
In the figure below, the central particle with charge q = -1 µC is surrounded by
-2q
two circular rings of radii 1.5 cm and 2 cm containing stationary charged
particles,.
A. Predict the magnitude and direction of the NET electrostatic force on the
central particle due to the other particles?
+q
-7q
B. If the mass of the central particle is the mass of an electron, calculate the
initial acceleration of the particle due to the net electrostatic force
+q
-2q
4.
Consider a firefighter trying to aim a water canon at an open window on the 5th floor
burning warehouse. The firefighter sets up the water canon 22.0 m
away from the base of the burning building and measures the open
window to be 15.0 m above the nozzle of the water canon. Assuming
the water leaving the canon is in freefall:
A. Predict initial velocity of the water such that it reaches the open window
at the apex of its parabolic trajectory.
B. Sketch kinematics graphs of the water’s Acceleration, Velocity and
Displacement vs. Time
for both horizontal and vertical dimensions.
2
-2q
+2q
-2q
+2q
of a
Los Altos Physics Spring Semester Final Exam Review
5
Mr. Randall
Consider an 0.111 kg rifle bullet traveling 200.0 m/s and colliding with a 4.00kg
wooden pendulum hanging vertically at rest at the end of a 3.00 m long cord.
After the perfectly inelastic collision the system pendulum swings upward in a
circular arc.
L
L
A.
Predict the maximum height of the bullet-pendulum system swings to.
B.
Predict the horizontal displacement of the bullet-pendulum system at it’s maximum
height.
V
h
o
∆
6.
Consider Tarzantha (55.0 kg) swinging on a strong jungle vine 35.0 m long. Tarzantha starts her
circular pendulum swing, from rest, 9.50 m above the lowest point in the swing. The instant Tarzantha
passes the lowest point in her swing she sneezes and yells out a pure tone of unknown frequency. An
observer standing at rest, at the same level of the lowest point in the swing, hears the sneeze and
measures the tone to be 4880 Hz.
A.
Derive an equation that predicts the Doppler shifted frequency heard by the
at rest observer.
a. Define variables.
b. Draw a clear diagram
c. Define λ’ or v’, whichever is responsible for the Doppler effect.
d. Substitute into the wave equation: V = λ f
e. Solve for f ’.
B.
Predict the frequency of Tarzantha’s sneeze.
C.
Write at least 1, but not more than three, complete sentences specifically
describing why the at rest observer hears the sneeze at a different frequency that Tarzantha originally
produced.
7.
Consider a model airplane (0.65 kg) suspended from a wire and rotating in a horizontal circle parallel to
the floor. The plane isn’t really flying, instead the tension provides all the forces necessary to keep it up
and turning in a circle. The radius of the circle is 3.20 m and the angle the wire makes with the
horizontal is 48º.
A.
Predict the total tension in the cable.
B.
Predict the plane’s speed around the circle.
C.
Predict the Time period of one revolution.
θ
r
3
Los Altos Physics Spring Semester Final Exam Review
8.
Mr. Randall
Consider a girl on an electric skate board, starting from rest and accelerating along a horizontal line.
Some distance away she grabs onto the bottom of a 13.8 m long rope and pendulum swings through a
90º angle and briefly stops. If the skateboard accelerates at 1.00 m/s2, predict the distance between
where she began skating to where she grabbed onto the rope.
L = 13.8 m
m
∆X
9.
Consider some circus clown starting at the top of a frictionless slide. If the clown starts from rest at
h = 8.4 m above the ground and the slide is inclined at θ=18.0° above the horizontal, then:
A. Predict the magnitude of the clown’s acceleration along the slide.
B. Predict the Length of the slide.
C. Predict the speed of the clown at the bottom of the slide.
D. Sketch and clearly label Acceleration, Velocity & Displacement vs. Time Graphs.
h
θ
10.
Consider an Alpha particle (He nucleus) entering, at right angles to a uniform magnetic field of 3.50 x
10-1 Tesla at a speed of 4.4 x 104 m/s. Assume the mass of a proton and a neutron are equal:
Mp = Mn = 1.67 x 10-27 kg
A.
B.
C.
D.
Predict the direction of the magnetic force initially acting on the Alpha particle.
What type of motion results when the net force is at right angles to the velocity?
Predict the radius of the circular path taken by the Alpha particle.
Predict the Alpha particle’s change in kinetic energy as it undergoes uniform circular motion.
v
Magnetically Shielded Tube
4
r
B=•