Master Physics with Fun Quizzes & Brain Teasers!

for an object that travels 60 meters east and then 60 meters west in fifteen minutes, what is the ratio of average velocity to average speed?
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a 2-kw electric resistance heater in a room is turned on and kept on for 30 minutes. the amount of energy transferred to the room by the heater is:
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n= 4.5 moles of an ideal gas are pumped into a chamber of volume v= 0.082m^3n= 4.5 molesV= 0.082m^3a) the initial pressure of the gas is 1 atm. what is the initial temperature (in k) of the gas ?b) the pressure of the gas is increased to 10 atm. now what is the temperature (in k) of the gas ?
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4. how can you use the slope of your best-fit line to determine the value of the permittivity of vacuum? derive the relationship between the slope and the permittivity.
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A 1kg1 ball swings in a vertical circle on the end of an 60cm long string. The tension in the string is 20N when its angle from the highest point on the circle is =30oa) What is the ball's speed when =30o?b) What is the magnitude of the ball's acceleration when =30o?c) What is the direction of the ball's acceleration when =30o? Give the direction as an angle from the r axis .
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what is the fluid speed (in m/s) in a fire hose with a 7.50 cm diameter carrying 81.0 l of water per second? m/s
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A generator connected to the wheel or hub of a bicycle can be used to power lights or small electronic devices. A typical bicycle generator supplies 5.50 V when the wheels rotate at = 19.0 rad/s. HINT (a) If the generator's magnetic field has magnitude B 0.550 T with N = 105 turns, find the loop area A (in m 2 m (b) Find the time interval (in s) between the maximum emf of +5.50 V and the minimum emf of-5.50 V
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An 800 kg white horse has the power output of 1 hp. The maximum force it can exert at speed of 3 meters second is 0.25 kilo-Newton's 2.20 kilo-Newton's 2.60 kilo-Newton 's3.60 kilo-Newton s
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if a spacecraft weighs 1,200 lbf on the moon (g=5.31 ft/s^2 ), what will be the approximate weight on phobos (g=0.0547 ft/s^2 ) be?
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What is the magnitude and direction of the net force on a car that has a force of 925N East and 358N West applied to it?a. 1283N Eastb. 567N Westc. 567N Eastd. 1283N West
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Suppose that an asteroid traveling straight toward the center of the earth were to collide with our planet at the equator and bury itself just below the surface. What would have to be the mass of this asteroid, in terms of the earth's mass $M$, for the day to become 25.0% longer than it presently is as a result of the collision? Assume that the asteroid is very small compared to the earth and that the earth is uniform throughout.
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4. compute the percent error between the calculated speed with the speed of light (c = 3.0 x 108 m/s)? is this close to the speed of light? explain why or why not.
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An electron and a proton are fixed at a separation distance of 949 nm. Find the magnitude and the direction of the electric field at their midpoint N/C The direction O cannot be determined is toward the proton O is perpendicular to the line of the particles. O is toward the electron
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which one of the following phrases best describes the term work function
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A 0.360-m-long metal bar is pulled to the left by an applied force F. The bar rides on parallel metal rails connected through a 45.0 ohm resistor, as shown in the diagram, so the apparatus makes a complete circuit. The circuit is in a uniform 0.650-T magnetic field that is directed out of the plane of the figure. At the instant when the bar is moving to the left at 5.90 m s, (a) is the induced current in the circuit clockwise or counterclockwise and (b) what is the rate at which the applied force is doing work on the bar?
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one of your classes at school takes place in the computer lab. you work on an assignment for an hour. the school lab has old desktop computers that use 100 watts/hour and large crt (tube) monitors that use 75 watts/hour.
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a person exerts a horizontal force of 76 n on the end of a door 82 cm wide. part a what is the magnitude of the torque if the force is exerted perpendicular to the door? express your answer using two significant figures.
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the orbital speed of the material in the solar nebula at pluto's average distance from the sun is about 5 km/s .what was the orbital speed of this material when it was 28,000 au from the sun (before it fell inward with the collapse of the nebula)? use the law of conservation of angular momentum. express your answer to two significant figures and include the appropriate units.
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A simple harmonic oscillation for a spring-mass system is described by x(t)= 3.4cos(8.2t+0.78) in SI units. The mass of the particle m=0.5kg. What is spring constant? a. 33.6 N/m b. 42.7 N/m c. 13.2 N/m d. 4.1 N/m e. none of above is within 5% from the correct answer.
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A 1000kg satellite orbits the Earth at a constant altitude of 100 km.How much energy must be added to the system to move the satellite into a circular orbit with altitude 200 km?
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a solar cooker, really a concave mirror pointed at the sun, focuses the sun's rays 18.8 cm in front of the mirror. what is the radius of the sperical sirface from which the mirror was made
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An airplane propeller is rotating at 1930 rev/min1.Compute the propeller's angular velocity in rad/s.2.How long in seconds does it take for the propeller to turn through 39 ??A turntable rotates with a constant 2.25 rad/s2angular acceleration. After 2.00 s it has rotated through an angle of 30.0 rad.1.What was the angular velocity of the wheel at the beginning of the 2.00-s interval?
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A capacitor has a peak current of 330 A when the peak voltage at 350 kHz is 2.8 V .Part AWhat is the capacitance?Part BIf the peak voltage is held constant, what is the peak current at 700 kHz ?
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"A rocket flies toward the earth at 0.5c and the captain shines a laser light beam in the forward direction.Which of the following statements about the speed of this light are correct? (There may be more than one correct answer.)An observer on earth measures speed 1.5c for the light.The captain measures speed 0.5c for the light.The captain measures speed c for the light.An observer on earth measures speed c for the light."
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