What must the charge (sign and magnitude) of a 1.43-g particle be for it to remain stationary when placed in a downward-directed electric field of magnitude 690 N/C ?

What is the magnitude of an electric field in which the electric force on a proton is equal in magnitude to its weight?

A stone is dropped into a well. The splash is heard 2.2 seconds later. What is the depth of the well to the nearest tenth of a meter?

1) You have a gyroscope and a string. Wind the string up and pull it fast to get the gyroscope spinning quickly. Try to turn the gyroscope upside down quickly. How does it feel different compared with doing the same thing when the gyroscope is not spinning? Finally, when it has slowed down a little (but not stopped) repeat the experiment. Does it feel the same when you try to flip the gyroscope at high speed versus low speed? Explain the physics of what is happening.

If 47.0 cm of copper wire (diameter = 1.00 mm) is formed into a circular loop and placed perpendicular to a uniform magnetic field that is increasing at a constant rate of 10.5mT/s, at what rate is thermal energy generated in the loop?

_______________ W

A block is at rest on an inclined plane whose elevation can be varied. The coefficient of static friction is μ_s= 0.45, and the coefficient of kinetic friction is μ_k = 0.18. The angle of elevation θ is increased slowly from the horizontal.

At what value of θ does the block begin to slide (in degrees)?

What is the acceleration of the block?

1. Kepler’s 3rd law.

(a) In an otherwise empty universe, two rocks of 5 kg orbit each other at a distance of 1m. What is their orbital period?

(b) The period of the Martian moon Phobos is 0.3189 d and the radius of the orbit is 9370 km. What is the mass of Mars?

When an oscillator is underdamped, there are two principle effects that we observe as a result (compared to the undamped oscillator). Describe them and explain why they occur?

A parallel-plate capacitor having plates 6.00cmapart is connected across the terminals of a 12.0Vbattery.

A. Being as quantitative as you can, describe the location of the equipotential surface that is at a potential of 6.00V relative to the potential of the negative plate. Avoid the edges of the plates.

d=

B. Do the same for the equipotential surface that is at 2.00V relative to the negative plate.

d=

C. What is the potential gradient between the plates?

E=

Select True or False to each of the following statements about this week's electric field mapping experiment. In order to receive credit for this question you must answer ALL statements correctly. NOTE: The number of attempts has been reduced on this question.
True False  Electric field lines can curve.
True False  All electric potemtials are measured with respect to the positive terminal of the power supply.
True False  The COM port of the digital multimeter (voltmeter) is connected to the positive terminal of the power supply via a banana to banana wire.
True False  The electric potential probe is connected to the positive terminal of the power supply.

1. The coils have the direction of the wrapped turns indicated on the top: if you look down from above the direction is clockwise. Using the right hand rule, what is the direction of the area vector for these loops of wire?

   		up
   		down
   		clockwise
   		counter-clockwise

Question 3

1. If the magnet is allowed to fall with its north pole down, that is, entering the coil first, in what direction does the magnetic field point?

   		up
   		clockwise (when viewed from above)
   		counter-clockwise (when viewed from above)
   		down

Question 4

1. Given the two directions in your answers to the previous two questions, what is the sign of the magnetic flux?

   		positive
   		negative
   		zero

Question 5

1. As the magnet enters, what will be the sign of the induced emf?

   		negative
   		zero
   		positive

Why do giant stars have much more narrow lines than main-sequence dwarfs?   Why are the stars that do not show
strong H Balmer lines either have either very low or very high surface temperatures?

Calculate the momentum p, kinetic energy K, and total energy E of an electron traveling at each of the speeds tabulated below.

Show how the terms of Bernoulli’s equation are related to Conservation of Energy?