We don't hear the squeaks of bats because their sound is
A) of ultra-high frequencies.
B) of ultra-high loudness.
C) both of these
D) neither of these
Answer: A
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An ideal gas composed of helium atoms is at a pressure of 2.00 atmospheres and a temperature of 35.0 
What is the mass density? (He = 4.00u)
A. 0.534 
B. 0.488
C. 0.400
D. 0.316
E. 0.276
Determine the rate of radiant heat emission in watts per square meter from a blackbody at (a) 150°C, (b) 600°C, (c) 5700°C.
GIVEN • A blackbody FIND The rate of radiant heat emission (qr) in W/m2 for a temperature of (a) T = 150°C = 423 K (b) T = 600°C = 873 K (c) T = 5700°C = 5973 K PROPERTIES AND CONSTANTS The Stefan-Boltzmann constant (?) = 5.67 ? 10–8 W/(m2 K4)
A metal rod of length L in a region of space where a constant magnetic field points into the page rotates about an axis through its center at constant angular velocity ?. The ends, A and E, make contact with a split ring that connects to an external circuit. The current in the external circuit of resistance R has magnitude
A.
B.
.C.
.D.
.E.
.Hardness is a comparative property that refers to the ability of a mineral to resist
a. fracturing. b. cleaving. c. scratching. d. crushing.