A coaxial cable consists of two long concentric
conducting tubes of length l, the inner one of radius a and the
outer one of radius b. Assume that the zˆ direction lies along the
axis of the cable. A current, I, flows down the inner conductor in
the zˆ direction and returns in the outer conductor, where in each
case the current is uniformly spread out over the surface.
(a) Determine the magnetic field B everywhere. [5]
(b) Find the self-inductance per unit length. [5]
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In a cathode ray tube, electrons are accelerated from rest by a constant electric force of magnitude 6.40 × 10−17 N during the first 4.40 cm of the tube’s length; then they move at essentially constant velocity another 45.0 cm before hitting the screen.
a.How long does it take them to travel the length of the tube?
b.Find the speed of the electrons when they hit the screen.
c.How long does it take them to travel the length of the tube?
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Summarize this experiment of pendulum from purpose to procedure
to analysis.
Within your answer, include the theoretical equations.
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Two protons, each having a speed of 0.910c in the laboratory, are moving toward each other.
a) Determine the momentum of each proton in the laboratory in GeV/c.
b) Determine the total momentum of the two protons in the laboratory GeV/c.
c) Determine the momentum of one proton as seen by the other proton GeV/c.
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What is the difference between the root-mean-squared velocity (????) and the average velocity (?̅) of gas particles?
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A regular icosahedron, as shown in the figure, has an outer
radius (defined as the distance from the centre to a vertex) of
9.51 cm and an inner radius (defined as the distance from the
centre to the centre of a face) of 7.56 cm. It has 20 faces which
are equilateral triangles with side length 10.0 cm, and 12
vertices.
Twelve negative charges of magnitude 20.0 μC are placed at the
vertices and 20 positive charges of magnitude 12.0 μC are placed at
the face centres. A positive charge of Q = +44.25 μC is placed at
the centre of the icosahedron.
What is the force acting on the charge at the centre of the icosahedron? [1]
If one of the negative charges at a vertex is removed, what is the force on the charge at the centre of the icosahedron? [2]
If one of the positive charges at the face is removed, what is the force on the charge at the centre of the icosahedron? [2]
Using your answers to parts ii) and iii) what is the net force on the charge Q at the centre if a complete face (i.e. one positive charge and the three surrounding negative charges), is removed? [5]
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Protons having a kinetic energy of 5.00 MeV (1 eV = 1.60 x 10-19 J) are moving in the positive x direction and enter a magnetic field B = 0.025 T directed out of the plane of the page and extending from x = 0 to x = 1.00 m as shown in the Figure below. (a) Ignoring relativistic effects, find the angle α between the initial velocity vector of the proton beam and the velocity vector after the beam emerges from the field. (b) Calculate the y component of the protons’ momenta as they leave the magnetic field.
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When we say that momentum is conserved for an isolated system, what specifically does that mean?
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The photogates in the experiment are used to determine the speed of the gliders passing through. The photogates measure the time it takes for the photogate beam to go from being unblocked to blocked to unblocked again. You tell the photogate how long your glider is, and the speed is then calculated.
Given the description of what the photogates do, how will you determine the velocity of the glider?
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A 7.50-kg box slides up a 25.0o ramp with an initial speed of 7.50 m/s. The coefficient of kinetic friction between the box and ramp is 0.333. You wish to calculate the distance the box will move up the ramp before coming to a stop using mechanical-energy (NOT force-motion or the work-kinetic energy.)
a. Write the correct equation for solving the problem, and then fully justify its use. (Start by identifying the objects in the system [only the required objects] and then proceeding as in class.)
b. Beginning with the equation in (a), calculate the desired distance.
c. Calculate the change in the thermal energy of the system as the box moves from the bottom of the ramp to where it stops.
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3Objectives•To determine the relationship between kinetic, potential, and total mechanical energy for a cart on an incline.•To determine the work done by friction on a sliding cart.•To show that energy is not conserved when a non-conservative force, like friction, is acting.Procedure: Energy of a cart withoutf riction In this experiment, we will assume that friction is negligible, and that there are no non-conservative forces at work.The motion of a cart rolling down an incline will be examined using real-time velocity and position values from a motion sensor. Examining the position and velocity of the cart as it rolls down the track allows us to also determine the energy of the cart. In this experiment you will examine the transition between gravitation potential energy and kinetic energy as the cart rolls down an incline.1.Figure 1 was set up in real time, where the ramp was inclined at an angle of 8.5°, and the mass of the cart is 0.250 kg. A Motion Detector was attached to the upper end of the track.As the cart slides down the track, the motion detector ispre-programmed to measure the distance (position) of the cart from the bottom of the ramp –see (d) infigure 1.2.Gravitational potential energy depends on position, and kinetic energy depends on velocity. The cart was released,and the position and velocity of the cart were measured with the motion sensor software. Time(seconds)Position(meters)Velocity(meters/second )
0.866658 1.273902 0.265542
0.899991 1.256238 0.471058
0.933324 1.239259 0.557238
0.966657 1.219022 0.618978
0.99999 1.197756 0.667428
1.033323 1.174775 0.720021
1.066656 1.14905 0.752035
1.099989 1.124183 0.771615
1.133322 1.098115 0.802199
1.166655 1.070846 0.8365
1.199988 1.042034 0.866512
1.233321 1.013222 0.901099
1.266654 0.982867 0.959695
1.299987 0.948738 1.006286
1.33332 0.915639 1.046589
1.366653 0.878766 1.080032
1.399986 0.842923 1.094753
1.433319 0.806908 1.141773
1.466652 0.766777 1.191794
1.499985 0.728361 1.266254
1.533318 0.682056 1.33071
43.Now, it’s time to plot the PE, KE, and total ME of the cart as
it rolls down the track.To do this, let’s first convert each
position, d, to a height so we can calculate the potential energy
of the cart. Open the data above in excel and create a new column
labeled height. Using equation 7,convert every position measurement
to the vertical height of the cart. In excel, make sure you use
0.1500983 (radians) for your angle, θ,Instead of 8.5°(degrees).
4.Create another new column titled Kinetic Energy. Create a formula which grabs each velocity value and, using your measured mass, calculates the kinetic energy of the cart(equation1).
5.Next, create another new column that calculates Gravitational Potential Energy as the cart rolls down the incline. Create a formula which multiplies the height by the mass of the cart and gravitational acceleration(equation 2).
6.Finally, create a third new column titled Mechanical Energy, which is just be the sum of your two columns, Kinetic Energy and Gravitational Kinetic Energy.
7.Create a line graph of kinetic energy versus time, potential energy versus time,and mechanical energy vs time on the same graph. Under your graph options, be sure to show a legend, so whoever reads your report will have no trouble determining which line is which.Attach the graph with your lab submission.
8.What is the approximately slope of your kinetic energy graph? What does this suggest about your cart’s kinetic energy as a function of time?
9.What is the approximately slope of your potential energy
graph? What does this suggest about your cart’s kinetic energy as a
function of time?
10.Analyze your graph carefully. What is the approximate slope of
your mechanical energy graph? What does this suggest about your
cart’s total mechanical energy?
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Refer to the illustration below. Light enters the stacked transparent plates at an angle of from the normal at location zero cm in the x direction.
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for materials class
Manipulating strength
a. Using words and visuals, briefly describe 4 strategies to increase the strength of a metal.
b. What do these strategies have in common in terms of their mechanism?
c. Use a plot to discuss the trade-off between strength and ductility in metals. Explain why this trade off occurs based on the mechanism of plastic deformation in metals.
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5 rems per year whole body occupational dose is the generally agreed limit by the standard setting bodies. State your opinions on this limit; do you agree with it?
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