At what temperatures values are the following scales the same? (a) The Fahrenheit and the Celsius (b) The Celsius and the Kelvin (c) The Fahrenheit and the Kelvin
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The coefficient of friction between the block of mass m1 = 3.00 kg and the surface in the figure below is μk = 0.455. The system starts from rest. What is the speed of the ball of mass m2 = 5.00 kg when it has fallen a distance h = 1.10 m?
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Describe how a lake freezes during winter. How do the fishes and other creatures in the lake avoid been frozen?
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What is the one property of dark matter we can measure? a) Color. b) Mass. c) Weight. d) Temperature. e) Chemical composition
How are the tiny temperature and density fluctuations in the cosmic microwave background (CMB) related to galaxies and clusters of galaxies we see in the present-day universe? a) There is no relationship. b) Warmer and denser regions in the CMB contain the least amount of dark matter. c) Warmer and denser regions in the CMB hide galaxies and galaxy clusters from our view. d) Warmer and denser regions in the CMB do not have enough hydrogen and helium to make present-day galaxies and galaxy clusters. e) Warmer and denser regions in the CMB are locations where galaxies and galaxy clusters are most likely to form
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1. Explain in details the three bands of the laser lines of the HeNE laser.
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Select all answers that correctly finish this sentence:
A FBD is a diagram that shows...
| a body isolated from its environment. |
| a body free of the forces acting upon it. |
| all of the external forces acting on a body. |
| the motion of the body as it freely moves through space. |
What is the Principle of Conservation of Linear Momentum?
| It is a reformulation of Newton's Second Law. |
| It says that the rate of change of linear momentum of a particle is equal to the net forces acting on the particle. |
| It says that if the net forces acting on a particle are zero, then linear momentum is conserved. |
| It says that if the net forces acting on a particle are zero, then linear momentum is constant. |
| All of the above. |
Angular momentum is to linear momentum as torque is to...
| force |
| moment |
| rotation |
| displacement vector |
Choose all of the names that refer to Angular Momentum.
| Moment of linear momentum. |
| Moment of momentum. |
| Angular torque. |
| Momentum. |
Select all of the quantities that must be known in order to calculate the angular momentum of a particle.
| The velocity of the particle. |
| The mass of the particle. |
| The position of the particle. |
| The point that the moment is calculated about. |
The Principle of Conservation of Angular Momentum is especially useful for what type of problems?
| Problems of particles moving under a central force. |
| Problems that use tangential and normal components. |
| Problems where the resultant moment of the forces about a fixed point is zero. |
| Both a and c are correct. |
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Which of the following describes the change in current from the primary circuit to the secondary circuit of a step-up transformer? a. The current in the secondary circuit is less than the current in the primary circuit. b. The current in the secondary circuit is equal to the current in the primary circuit. c. The current in the secondary circuit is greater than the current in the primary circuit. d. none of the above
A step-up transformer is used to change the voltage produced by a generator from 30 kA to 300 kA. The amount of power produced after the voltage increase is 600 MW and the energy is then sent through a transmission line with a resistance of 0.2 W. How much power is lost in transmission? a. 1 MW b. 0.8 MW c. 0.4 MW d. 0.6 MW
What could happen during power transmission if the voltage is too high? a. There will not be enough current to travel through the wires. b. The magnetic field that is induced could interfere with satellite communications. c. It would be impossible to step down to a level for home usage. d. The energy could discharge through the air and to the ground.
thank you so much.
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A highway is to be built between two towns, one of which lies 33.5 km south and 70.8 km west of the other. (a) What is the shortest length of highway that can be built between the two towns, and (b) at what angle would this highway be directed, as a positive angle with respect to due west?
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What will power the cars of tomorrow (in about 10 years, ~2030)? Choose and describe one energy source. 1 point Explain the reasons for your choice and identify the advantages and disadvantages of "tomorrow's" cars power supply (not just in the vehicle but at the fuel's / power supply's source). 5 points
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Solve the differential equation y'''-3y''+4y=e2x using variation of parameters and wronskians. Please provide steps especially after finding the wronskians.
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-Derive the law of the conservation of momentum using Lagrange Formalism.
-Derive also the conservation of the angular momentum
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An Uncontrolled Full-Wave full-bridge rectifier with
RL-Source load and Discontinuous load
current is to be designed based on the following assumptions and
constraints. Design the circuit
and calculate the parameters of the rectifier based on the
following assumptions and constraints.
Simulate the designed rectifier in PsPice and compare the simulated
and the calculated results.
a) The AC source is 220 V rms at 50 Hz. Vdc= 65 V, power absorbed
by the resistor is 360
W.
b) The AC source is 220 V rms at 50 Hz. Vdc= 70 V, power absorbed
by the resistor is 400W.
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A plunger cylinder device contains 50 L of liquid water at 50 oC and 180 kPa. Heat is transferred to the water until 40% of the liquid evaporates. Determine the work done by the system during this process and explain the physical meaning of the sign of its result.
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