Consider a solid sphere with radius R with a charge uniformly spread throughout its volume. The magnitude of the sphere’s electric field is at a point P1 on the sphere’s surface and is at a point P2 at a distance R from the sphere’s center. In the relationship

src="https://sciemce.com/media/4/0bceea0c4116d7d2019-09-09 19_24_08-ch02_clicker [Compatibility Mode] - Microsoft PowerPoint.png" class="w-image" /> , what is the value of b?

A. 0
B. 1
C. 2
D. 4
E. 8
F. Other

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C. 2

Physics & Space Science

Because electromagnetic radiation (EMR) of sufficient energy can excite electrons from stable orbitals, EMR is considered to travel in packets of energy called _________.

Fill in the blank(s) with the appropriate word(s).

A thermocouple (0.8-mm-OD) is located horizontally in a large enclosure whose walls are at 37°C. The enclosure is filled with a transparent quiescent gas that has the same properties as air. The electromotive force (emf) of the thermocouple indicates a temperature of 230°C. Estimate the true gas temperature if the emissivity of the thermocouple is 0.8.

GIVEN
• Horizontal thermocouple in a large enclosure
• Thermocouple outside diameter (D) = 0.8 mm = 0.0008 m
• Enclosure wall temperature (Te) = 37°C = 310 K
• Gas is enclosure is quiescent and has the same properties as air
• Thermocouple reading (Ttc) = 230°C = 503 K
• Thermocouple emissivity (?) = 0.8
FIND
• True gas temperature (T?)
ASSUMPTIONS
• Enclosure behaves as a black body
• Conduction along the thermocouple out of the enclosure is negligible
SKETCH

PROPERTIES AND CONSTANTS
The Stephan-Boltzmann Constant (?) = 5.67 ?10–8 W/(m2 K4).

What is the change of entropy associated with 3.0 kg of water freezing to ice at 0.°C?

A) -1.1 kcal/K B) -0.88 kcal/K C) 0 kcal/K D) 1.0 kcal/K E) +0.88 kcal/K

The ionic layers of the atmosphere reflect

a) radio waves. b) charged particles. c) sound. d) light.