Immediate!! An induction motor has the following parameters.
Determine the maximum transient torque that can occur when the 100 hp motor is plug reversed (sudden reversal of the excitation phase rotation). Assume the machine is running in the steady state with rated load prior to the plugging and that the load torque is constant over the interval of interest. Also assume that all three phases disconnect and connect simultaneously and that the time between opening and closing can be varied. Compare the simulation results with an approximate solution using the trapped rotor flux model.
460 V (lin-to-line), 100 HP, 60 Hz, 4-pole, r s =r r =0.0425 ohm, L s =L r =23.33 mH, L m =22.57 mH, J=2 kg-m 2 Rated slip: s R =0.0177, rated stator current I R =109.5 A, rated power factor: 0.88.
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A cannon is shot at 48 m/s at an angle of 30 degrees to the horizontal off a cliff that is 78.4 meters tall. How fast will the cannonball be moving when it hits the ground at the bottom of the cliff?
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#2
a. Consider a Michelson interferometer with one fixed arm and one moveable arm, both of length 5 m. If 300 nm laser light is shown through the device, what percentage change in the length of the movable arm will shift the detector from constructive to destructive interference?
b. A telescope is looking at a 2 star system. If the stars are 1.5 x 10^13 m apart and 9 x 10^16 m away, how big does the telescope opening have to be to resolve the two stars?
c. If red light (lambda = 800 nm) and violet light (lambda = 400 nm) are alternately shown through a slit with width 1 mm, find the distance between the first minima for these different lights on a screen 5 m away.
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A prism made of flint glass has a cross section that is an equilateral triangle. The index of refraction for red and violet light respectively in flint glass is 1.662 and 1.698. If as shown in the figure, the angle of incidence in air for both colors of light is 75.1
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1. Cite 2 examples of entropy increase in daily life.
2. Find 2 examples of probability governing events in everyday events.
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Respond to the following:
In your own words, explain direct current, resistance, Ohm's Law, electromotive force, and resistors in series and in parallel. Also give examples.
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A 0.0210 kg bullet moving horizontally at 500 m/s embeds itself into an initially stationary 0.500 kg block.
(a) What is their velocity just after the collision?
_____ m/s
(b) The bullet-embedded block slides 8.0 m on a horizontal surface
with a 0.30 kinetic coefficient of friction. Now what is its
velocity?
_____ m/s
(c) The bullet-embedded block now strikes and sticks to a
stationary 2.00 kg block. How far does this combination travel
before stopping?
____ m
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Please answer these questions:
1) What determines the number of significant figures in an experimental measurement?
2) How do we find experimental uncertainty in measurement?Why is this important?
3) What is easier to measure, the diameter or the radius of a ball,
and why?
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(Solid state physics)
What is a BASIS in a "conventional unit cell" of BCC??
(Not in a primitive cell of BCC)
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mechanics
research about the following terms, support your research by
calculations and diagrams were possible
1.force
2.force characteristics
3.force systems
4.concurrent forces
5.co-planar forces
6.resultant of concurrent forces
7.components of a force
8.moment of a force
9. laws of static equilibrium
10.beams
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Find the correlation that gives the critical state of the homogeneous spherical reactor with "diffusion effect cross section ∑s" and "fission effect cross section ∑f", "diffusion coefficient D" and radius R.
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Recall the behavior of the compass needle as you explored the magnetic field created by the coil. Indicate which two of the following five statements are true. Select one or more: a. It is not possible to decide which end of the coil is a magnetic North when current is flowing through the coil. b. If I always move in the direction indicated by the compass needle, thus following a given field line, my path will trace a loop going around the coil without entering it and returning to my point of departure. c. If I always move in the direction indicated by the compass needle, thus following a given field line, my path will trace a loop going through the inside of the coil and returning to my point of departure. d. As the compass enters one end of the coil, the needle first aligns with the axis of the coil and its orientation reverses as you move the compass along the interior of the coil and exit at the other end. e. As the compass enters one end of the coil, the needle aligns with the axis of the coil and its orientation does not change as you move the compass along the interior of the coil and exit at the other end.
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it's a hot day. you buy four fans and plug them into outlets. the outlets are powered by a circuit protected by a 20A circuit breaker. if each fan is rated at 250W and the outlet voltage is 120V, will the circuit breaker interrupt current flow?
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Although the injuries tend to be less severe, heading a soccer ball carries many of the same dangers as getting hit by a blocker or tackler in a football game. Indeed, heading is now forbidden in many youth leagues. In a very simple model, calculate the impulse given to the skull and its average acceleration when struck by a soccer ball. Assume that a headed soccer ball undergoes an elastic collision lasting 0.7 ms in which it reverses direction. Consider two different heading techniques: (i) where the head effectively recoils on its own, independent of the body (ii) the head and body recoil together. Do calculations for both youth players and for adults.
Youth Adult
Soccer ball mass (kg) 0.375 0.425
Speed of kicked ball (m/s) 20 35
Mass of skull (kg) 3 5
Mass of entire body (kg) 30 60
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why do the maximum and minimum momenta have opposite signs? like cart 1 hitting cart 2 why would cart one be positive and cart to be negative?
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