Master Physics with Fun Quizzes & Brain Teasers!

A 500 hp, three-phase, 2200 V, 60 HZ, 12-pole, Y-connected, wound-rotor induction motor has the following parameters:R1 = .225 ohm : R'2= .235 ohm Xeq = 1.43 ohm and Xm = 31.8 ohm and Rm = 780 ohmCalculate the following:(a) Slip at maximum torque(b) Input current and power factor at maximum torque(c) Maximum torque(d) Resistance that must be added to the rotor windings (per phase) to achieve maximum torque at starting
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A car of mass 1500kg rounds a curve of radius 250m at 90km/hr. Calculate the centripetal force acting on it.
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Never shine a green laser at anyone, especially not at an airplane, since the pilots can see the beam. Some fool did this in 2002, and the F. B. I. arrested him on domestic terrorism charges.Suppose that a green laser shines light with = 5.32 107 m. This light travels outward from the laser through a circular aperture that is 2.50 mm in diameter. How many meters in diameter is the beam, at a jet airliner altitude of exactly 38,000 feet? (Recall that 1 foot = 0.3048 m.)
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which of the following cart configurations could produce the x vs t graph shown? position graph four carts a. cart a b. cart b c. cart c d. cart d
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Our best measurements from Earth indicate that the star system Alpha Centauri is 4.2 lightyears (ly) away: Suppose some of our astronauts traveled there at a speed v 0.95c. What would the astronauts measure as the distance to Alpha Centauri? 75.2 ly 5.2 ly 56.5 ly 1.3 ly 2.6 ly
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(2 points) type i and type ii supernovae are respectively caused by what types of stars?
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The Velocity V of Sound travelling along a road made of a material of young's modulus and density f is given by V= [tex] \sqrt{} [/tex]rq show that the formula is dimensionally Consistent.
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Suppose that a grandfather clock has a pendulum with a length of 1.5m. You find that the clock runs fast so that it gains 10 seconds every hour. How much should the pendulum be lengthened to run on time?
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38. (WAEC 1994) A car fuse is marked 15 A and operates normally on a 12 V battery. Calculate the resistance of the fuse wire.
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g a light ray travels from a type of glass into air if the angle of incidence is 23 what is the angle of refraction round your answer to two decimal places
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Suppose the decay constant of radioactive substance A is twice the decay constant of radioactive substance B. If substance B has a half-life of 4hr, whats the half-life of substance A?
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which units would not be appropriate for describing a rotational acceleration: rad/s, rev/s^2,rev/m^2, degrees/s^2? explain
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how much impulse stops a 54- kg carton sliding at 3.4 m/s when it meets a rough surface?
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an engine starts at 100 rad/s of angular velocity and uniformly accelerates to 400 rad/s in 7.0 s. find its angular acceleration in rad/s/s.
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A car of mass 2000 kg is moving with a constant velocity of 10 m/s due east. What is the momentum of the car?
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at what speed does a clock move if it is measured to run at a rate three-fourths the rate of a clock at rest with respect to an observer?
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the maximum clock frequency, given a critical path of 10 ns, is f = _____ mhz ?
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1. Two stars with similar temperatures but different sizes will have a. similar spectral types but different luminosities. b. similar luminosities but different brightnesses. c. similar brightnesses but different distances. d. similar distances but different masses. e similar masses but different spectral types
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g consider a coulomb damped system with a natural frequency of 100 rpm. if the decay per cycle is 0.04, calculate the kinetic friction coefficient. which of the following is the correct answer for the kinetic friction coefficient. please submit your hand calculations into the dropbox.
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A concave mirror of radius of curvature 10 cm is placed 30 cm from a thin convex lens of focal length 15 cm. Find the location and magnification of a small bulb sitting 50 cm from the lens by using the algebraic method.
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why do you think neither love withdrawal nor power assertion were particularly effective at promoting moral maturity, but induction was
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if cobalt-60 have an initial decay-rate of 20 ci about 15 years ago, what would be the approximate strength of the source now. take the half-life of source as 15 years?
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A 67 ohm resistor, an 8.4 /muF capacitor, and a 31 mH inductor are connected in series in an ac circuit.Part ACalculate the impedance for a source frequency of 300 Hz.Express your answer to two significant figures and include the appropriate units.Part BCalculate the impedance for a source frequency of 30.0 kHz.Express your answer to two significant figures and include the appropriate units.
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Where should a presence-sensing device be placed on the press of Exercise? Exercise A part-revolution clutch press has a brake stop time of 0.37 second. At what minimum distance should two-hand controls be placed? If the press of Exercise had been a full-revolution press operating at 60 rpm and having four engagement points, at what distance should a two-hand trip device be placed?
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