Infra-red radiation is produced by
A) mechanical oscillators that move air back and forth.
B) molecules in thermal motion.
C) nuclear vibrations.
D) electric currents oscillating in human-made electronic devices.
E) electrons orbiting around the nucleus in atoms.
B
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Dye penetrant is an effective method to detect _________cracks.
Fill in the blank(s) with the appropriate word(s).
A physicist claims that she has found a new particle with a mass 200 000 times the mass of the proton (1.67 × 10^?27 kg) and a charge of 3.20 × 10^?19 C. If she is correct, such a particle traveling in a circle in a uniform 5.00 T magnetic field at a velocity of 2 500 m/s will have a radius of
a. 0.261 m. b. 0.522 m. c. 1.04 m. d. 3.27 m. e. 3.13 × 10^26 m.
Three identical 6.0-kg cubes are placed on a horizontal frictionless surface in contact with one another. The cubes are lined up from left to right and a force is applied to the left side of the left cube causing all three cubes to accelerate to the right at 3.0 m/s2 . What is the magnitude of the force exerted on the middle cube by the left cube in this case?
a. 18 N c. 54 N b. 27 N d. none of the above
What is the equivalent capacitance of the combination shown?
a.
20 ?F
b.
90 ?F
c.
22 ?F
d.
4.6 ?F
e.
67 ?F