A heat engine receives an amount of energy Qh= 790 kJ by heat transfer from a high temperature thermal reservoir at Th=950 K. Energy is rejected by heat transfer to a lower temperature thermal reservoir at T1=590 K. If waste heat in the amount of Q1=160 kJ is rejected to the low temperature thermal reservoir during each cycle.
a) Solve for the maximum theoretical efficiency that an engine in this situation could operate with. ANSWER: 0.379
b) Solve for actual efficiency that the engine is operating with.
c) Which of the following best describes the manner in which the cycle is operating...
-Reversibly or Impossibly?
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The two blocks, m1 = 2.6 kg and m2 = 4.2, in the figure below are connected by a massless rope that passes over a pulley. The pulley is 12 cm in diameter and has a mass of 2.0 kg. As the pulley turns, friction at the axle exerts a torque of magnitude 0.55 N · m. If the blocks are released from rest, how long does it take the 4.2 kg block to reach the floor from a height of h = 1.0 m? (Note: If your random numbers do not create movement between the masses enter 0 for your answer.)
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A simple pendulum of length 0.50 m has a 0.30-kg bob. At t = 0, the bob passes through the lowest position in its motion, and at this instant it has a horizontal speed of 0.39 m/s . A. What is the maximum angular displacement ϑmax away from vertical that the pendulum reaches? B. What is the magnitude of the bob's linear speed v when it has angular displacement ϑmax/2?
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Which of the descriptions below is an example of resonant energy transfer? (Choose all that are correct.)
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Hint 1.
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Review natural frequency and resonance.
Which of the descriptions below is an example of resonant energy transfer? (Choose all that are correct.)
| A block sliding on a horizontal surface slows down and comes to a stop due to the friction force. |
| Soldiers marching in unison on a bridge with their steps at a frequency that is very different than the natural vibration frequency of the bridge. |
| A vibrating pendulum connected to a very similar second pendulum influences the vibration of the second pendulum. The amplitude of vibration of the first pendulum decreases and the amplitude of the second increases. This exchange of amplitude and energy keeps happening back and forth between the two pendulums. |
| Ultrasound machines are used to apply a variable force at a frequency that matches the natural frequency of gall stones, causing the gall stones to vibrate and break up. |
| A box is pushed with a constant force down an empty abandoned hallway and its speed increase. |
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During typical urination, a man releases about 400 mL of urine in about 30 seconds through the urethra, which we can model as a tube 4.0 mm in diameter and 20 cm long. Assume that urine has the same density as water, and that viscosity can be ignored for this flow. What is the flow speed in the urethra? If we assume that the fluid is released at the same height as the bladder and that the fluid is at rest in the bladder (a reasonable approximation), what bladder pressure would be necessary to produce this flow? (In fact, there are additional factors that require additional pressure; the actual pressure is higher than this.)
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Determine the most probable interaction for the following: a. 30 kev photon on calcium b. 100 kev photon on iodine c. 300 kev photon on water d. 10 Mev photon on lead
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please rephrase/ rewrite this paragraph and you can add your own ideas
''Power plants all across the country are connected to each other through the electrical system. These power stations are responsible for generating electricity for many homes and buildings which are all interconnected through the network of wires we refer to the electrical grid. The methods in use for generating electricity varies with location or power station preference but, then main two ways are fossil fuels and gas. Other methods include nuclear power, hydroelectric generations, wind turbines, magnetic coils and more recently solar power. One way to look at electricity in cities is as one large body of water spilling into small pond. The network of ponds is actually a continent sized network of high voltage power lines and the houses, businesses, and factories get electricity from that grid. Until recently, electric energy could not be stored in the grid. The pond analogy also works at it suggests that water flow one direction. The electric current in the grid is alternating current, meaning it rapidly switches directions. However, the overall power itself flows from plants to house the same way water would flow from a stream into a small ponds. The large stream contributes to the one network of ponds, and all houses draw from the same network. This is how it works with power plants, the electric grid, and the houses using electricity. The electrical charge goes through high voltage transmission lines that stretch across the country. The voltage is lowered so it can be sent onto smaller power lines. It travels through distribution lines to neighborhoods, where smaller pole top transformers reduce the voltage again to make the power safe to use in our homes. There are also transformers at work on the other end. Their job is to drop the voltage back down to safer and more usable levels. A meter is used to measure how much each family uses. The electricity goes to service panel in your basement or garage, where breakers or fuses protect the wires inside your house from being overload. The electricity travels through wires inside the walls to the outlets and switches all over your house.''
upload your work as picture. Thank you so much
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Calculate the temperature of a planet. A star has a surface temperature of 4000K and a radius of R = 8 × 108 m It has a rocky, airless planet orbiting it at a distance of 1.0×1011 meters. The planet has a radius of 5.0 × 106 m. We will estimate 1 for all objects. (a) What is the total power output of the star?
(b) What is the power incident on each square meter at distance to the planet (i.e. on an imaginary sphere).
(c) How much power is absorbed by the planet? (Assume the planet is black. Use the fact that the planet looks like a disk.)
(d) In equilibrium, Pin = Pout. How much power does the planet radiate per square meter of surface area of the planet?
(e) What is the temperature of the planet? (Should humans try to live there?)
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Examples, please Paired design with repeated measures Paired design with matched pairs
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Very detailed explanation on how a battery operates. The theory in the internal resistance of batteries, how charge is created, EMF, Electrochemical reaction in batteries, etc.
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Suppose the electric field between the electric plates in the mass spectrometer of Fig. 20-38 is 2.38 ? 104 V/m and the magnetic fields B = B' = 0.66 T. The source contains carbon isotopes of mass numbers 12, 13, and 14 from a long-dead piece of a tree. (To estimate atomic masses, multiply by 1.67 ? 10-27 kg.)
A) How far apart are the lines formed by the singly charged ions
of each type on the photographic film?
mm
(b) What if the ions were doubly charged?
mm
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What is the phenomenon of differential negative resistance (negative differential resistance) and how can it be used in electronic devices? Please explain it in two or three paragraphs
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A solid, uniform cylinder with mass 8.25 kg and diameter 10.0 cm is spinning with angular velocity 245 rpm on a thin, frictionless axle that passes along the cylinder axis. You design a simple friction-brake to stop the cylinder by pressing the brake against the outer rim with a normal force. The coefficient of kinetic friction between the brake and rim is 0.344.
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Pose a situation (only one) problematic of real life, where you need mechanical physics to solve it. Situations similar to those we have been working on in the previous activities
The problem posed must contain the following topics, without being limited to this list:
1. Conservation of Mechanical Energy
2. Conservation of the linear or two-dimensional Moment.
3. Conservation of the angular Moment.
Rubric to evaluate problem-based learning activities PROBLEM-BASED
It shows a real situation, original and with a lot of creativity.
It shows a detailed design of the situation, where it includes all the physical variables contemplated.
The problem situation includes issues of Conservation of mechanical energy, conservation of momentum and conservation of angular momentum.
Shows the calculations evidencing the issues requested for the problem.
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A 150-kg satellite is in circular orbit of radius 7.3 Mm around Earth. Determine:(a) potential, kinetic, and total mechanical energies.(b) the orbital speed.(c) the escape velocity from this altitude.
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