How does an ammeter, a voltmeter, and an ohmmeter work. Shunt resistance, etc.

The Earth’s magnetic field undergoes periodic reversals. How was this discovered, and by whom? What is the current best theory of its cause?

Bob is in a gravitational potential well, he moves a long vertical stick up and down a distance of 1 meters. Alice observes the upper end of the stick, at upper location.

There is the phenomenon of redshift of energy, so either Alice measures a shorter motion than 1 meters, or alternatively Alice measures a weakened force.

So I'm asking: is Bob weak, or is Bob short?

Three astronauts, propelled by jet backpacks, push and guide a 123 kg asteroid toward a processing dock, exerting the forces shown in the figure, with F₁ = 35 N, F₂ = 55 N, F₃ = 40 N, θ₁ = 30°, and θ₃ = 60°. What is the (a) magnitude and (b) angle (measured relative to the positive direction of the x axis in the range of (-180°, 180°]) of the asteroid's acceleration?

A photon of wavelength 0.65037 nm strikes a free electron that is initially at rest. The photon is scattered straight backward. What is the speed of the recoil electron after the collision?

1.) Motors and generators  

a) In a homopolar motor (like Faraday’s motor), what happens to the motion if the current is reversed?

b) Who was William Sturgeon and what was his connection to motor improvement?

c) What is the voltage induced in a generator with 974 turns, an area of 195 mm² turning at a rate of 42 rpm with a constant field of 0.0209 T?

A U-shaped tube is filled mostly with water, but some vegetable oil has been added to both sides of the U tube. On the right side of the tube, the depth of oil is 7.00cm . On the left side of the tube, the depth of the oil is 2.80cm . The density of the water is 1.00

a) A ball of charge +q is placed on the x-axis at x=0. A second ball of charge +16q is placed on the x-axis at x = -2a. A third ball , with a charge that has a magnitude of q, is placed on the x - axis at a n unknown location . If the net electrostatic force exerted on the ball at the origin due to the other two balls has a magnitude of 5kq^2/a^2, what is the location of the thir d ball and the sign of the third ball

Discussion Question 1:

Discuss the differences between the Einstein’s Theory of Relativity and Classical Physics Theory (i.e. Galileo and Newton, etc.)

Discussion Question 2:

Discuss the wave-particle duality of light and its implications. What are possible industrial applications?

Three uniform sticks, each of mass m, are placed on the floor as follows: stick 1 lies along the y axis from y = 0 to y = 3.5 m , stick 2 lies along the x axis from x = 0 to x = 3.5 m , stick 3 lies along the x axis from x = 3.5 m to x =7.0 m .

A.Find the x-coordinate of the center of mass of the sticks.

B.Find the y-coordinate of the center of mass of the sticks.

C.How would the location of the center of mass be affected if the mass of the sticks were doubled? Explain

A car starts from rest at a stop sign. It accelerates at 2.0 m/s2 for 6.3 seconds, coasts for 3.0 s , and then slows down at a rate of 1.5m/s2 for the next stop sign.

a) How far apart are the stop signs?

Express your answer with the appropriate units.

Physics Question:

Write a brief (one to two paragraph) essay discussing what a physicist means by a "force". Include a discussion of what the different kinds of forces are that we have talked about in this class and some of their properties.

A whale swims at a constant velocity of 15 m/s southeast for 10 seconds, slows to a stop at a rate of 3 m/s^2, and then accelerates northwest at a rate of 2 m/s^2 for 5 seconds.

(a) sketch the velocity versus time t for the entire motion. Assume the motion started at time t=0 seconds;

(b) how long did the motion described last?;

(c) find an expression of the whale's velocity as a function of time for the entire motion;

(d) find an expression for the whales acceleration as a function of time for the entire motion;

(e) sketch the acceleration as a function of time;

(f) find an expression for the whale's average velocity over any time interval [0,t] during the motion;

(g) find the expression fo the whale's displacement as a function of time; and

(h) sketch the displacement versus time for the entire motion.

A. A sphere and a cylinder roll down an inclined plane, started from rest at the same time. They have the same radii, but not the same mass. Does one reach the bottom first? If so, which? Explain your reasoning.

B. Two spheres roll down an inclined plane, starting from rest at the same time. Sphere A has radius R and mass m. Sphere 2 has radius 2R and mass m. Does one reach the bottom first? If so, which? Explain your reasoning.

An electron moves with a speed of 3.0