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View Article  Photon Energies
View Article  Radiated Energy
If the absolute temperature of a blackbody is increased by a factor of three, the energy radiated per second, per unit area:

(1) decreases by a factor of 9

(2) increrases by a factor of 9

(3) increases by a factor of 27

(4) decreases by a factor of 81

(5) increases by a factor of 81
View Article  Destructive Interference
Two idenical speakers driven by the same signal produce 680 Hz soundwaves.  The speakers are different distances away from you.  What must be the difference in distances to result in destructive interference?

(1) 0.85 m

(2) 1.3 m

(3) .30 m

(4) .25 m
View Article  Blow my Horn
An engineer in a moving train blows the train's horn while the train is moving away from a woman standing on a nearby platform. Compared to the frequency of the sound that the engineer hears, the lady standing on the platform hears a sound with:

(1) the same wavelength

(2) more variation in tone

(3) greater amplitude

(4) a lower frequency
View Article  Force
A college soccer star runs towards the opposing goal and kicks a 0.5 kg stationary inflated ball with a total force of 50 newtons.  What is the force on the athlete's foot?

(1) 0 N

(2) 25 N

(3) 50 N

(4) 100 N
View Article  Stored Energy
A 3 microfarad capacitor is connected with a 6 microfarad capacitor. When a 300 volt potential difference is applied across this combination, the total energy stored in the two capacitors is:

(1) 0.41 J

(2) 0.27 J

(3) 0.09 J

(4) 0.81 J

(5) 0.18 J
View Article  Acceleration
A net force of 10 newtons accelerates an object at 5.0 meters per second2. What net force would be required to accelerate the same object at 1.0 meter per second2?

(1) 1N
(2) 2N
(3) 5N
(4) 50N
View Article  Friction
A snowboarder starting at rest comes down a slope at an angle of 30 degrees with the horizontal. The skier makes a total vertical descent of 100 m and then coasts along a level section which runs for 400m before entering the beginner's area.

(1) How large must the coefficient of friction be to just prevent the aggressive snowboarder from entering the learning area, and wreaking havoc?

(2) Using the coefficient of friction found in (1) what is the maximum velocity that can be attained by the snowboarder?
View Article  Playing with Water
Which quantity is equivalent to the product of the absolute index of refraction of water and the speed of light in water?

(1) frequency of light in water
(2) sine of the angle of incidence
(3) speed of light in a vacuum
(4) wavelength of light in a vacuum