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
You might also like to view...
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
Dye penetrant is an effective method to detect _________cracks.
Fill in the blank(s) with the appropriate word(s).