Physics 513Name ______
VaughanFinal Exam Long Answer Review
These questions were written by former students of mine after a brainstorming session of what types of questions they anticipated seeing on the final exam.
1. A 40 kg cannonball is fired at a 65o angle from a flat plane with an initial speed of 100 m/s.
a) Find the total time of travel.
b) Find the total horizontal displacement.
c) What is the shape of the path?
d) At the peak, what is the direction and magnitude of the net force on the cannonball?
2. Use the following circuit to answer the following questions:
VT = 60 V
R1 = 10 Ω
R2 = 20 Ω
R3 = 24 Ω
a) Find the equivalent resistance for the circuit.
b) Find the current through the battery.
c) Find the potential drop across resistor 1
d) Find the current through resistor 2
e) Find the rate at which energy is dissipated at resistor 3
f) Draw the appropriate meter to measure
- the current through resistor 3
- the potential drop across resistor 1
3) A boy is standing near the edge of a cliff and tosses a toy directly upward at a speed of 40 m/s. The cliff is 35 meters tall. The toy finally lands at the bottom of the cliff.
a) Find the total time of travel.
b) Find the velocity of the toy just before it strikes the ground.
c) Sketch a graph of velocity vs. time. Be sure to label any important values on the axes.
4) A 60 kg wood block is placed on an inclined plane which is also made of wood. The coefficient of kinetic friction is 0.30. The angle of inclination is 25o. (Note, there IS friction in this problem)
a) Draw a free body diagram.
b) Find the magnitude of the normal force.
c) Find the magnitude of the frictional force.
d) Find the acceleration of the block down the plane.
5) A 50 kg mass is moving north at 4 m/s. A 60 kg mass moves south at 3 m/s. They collide inelastically.
The interaction lasts for 0.040 seconds. (All answers need magnitude and direction)
a) What is the initial momentum of the system?
b) What is the final velocity of the combined mass?
c) What was the force on the 50 kg mass?
6) A 65kg man is in a rollercoaster car that is initially at rest. The man is (of course) sitting on a scale.
The height of the initial hill is 80 meters. Both the first dip and second hill approximate circles with radii of 20 meters. The second hill is 40 meters high.
B
A
a) Find the speed of the man at the bottom of the first dip. (point A)
b) At point A, find the reading on the scale.
c) Find the speed of the man on the top of the second hill. (point B)
d) Does the car safely make it over the second hill without losing contact?
7) Light with a frequency of 3.8 x 1014 Hz is travelling in air. It strikes a boundary with crown glass at a 40o angle to the normal.
a) What is the wavelength of this light in air?
b) What color is this?
c) What is the angle of refraction in crown glass?
d) Draw a ray diagram with a protractor. Label everything.
e) Find the speed of light in crown glass.
f) What is the wavelength of the light in crown glass?
8) Light with a frequency of 9 x 1015 Hz is incident on a diffraction grating that has an average slit separation of 2.5 x 10-5 meters. A screen is placed 6 meters from the grating.
a) What is the wavelength of the incident light?
b) What is the separation distance between successive adjacent maxima?
c) What does this experiment prove?
d) If light was a photon, what would be the energy of a photon of this light in electronvolts?
9) Light with a wavelength of 600 nm is incident on a charged metal plate that has a threshold frequency of 2 x 1014 Hz.
a) What is the minimum energy of photon that would cause this plate to emit photons?
b) What is the energy of the photons incident on this plate?
c) Show that electrons will be emitted. Find the maximum kinetic energy of the emitted electrons in both Joules and electronvolts.
d) What could be done to cause the plate to release MORE electrons?
e) Find the speed of the ejected electrons.