How does silica content effect volcanic eruptions?
What will be an ideal response?
Answer: Silica content greatly effects magma viscosity. The greater the silica content, the greater the viscosity (resistance to flow). Magmas with a high silica content flow slowly, while magmas with a low silica content tend to flow more easily. As such, basaltic eruptions (low silica content) are very fluid while andesitic eruptions (high silica content) flow slowly. The high resistance to flow can act as a trap to gases in the magma that, as pressure builds up, can cause the volcano to erupt explosively.
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A high-speed computer is located in a temperature controlled room of 26°C. When the machine is operating its internal heat generation rate is estimated to be 800 W. The external surface temperature is to be maintained below 85°C. The heat transfer coefficient for the surface of the computer is estimated to be 10 W/(m2 K). What surface area would be necessary to assure safe operation of this machine? Comment on ways to reduce this area.
GIVEN
• A high-speed computer in a temperature controlled room
• Temperature of the room (T?) = 26°C
• Maximum surface temperature of the computer (Tc) = 85°C
• Heat transfer coefficient (U) = 10 W/(m K)
• Internal heat generation q
G= 800 W
FIND
• The surface area (A) required and comment on ways to reduce this area
ASSUMPTIONS
• The system is in steady state
SKETCH
Which of the following ranges corresponds to the shortest wavelengths?
a. infrasonic c. ultrasonic b. audible d. All have the same wavelengths.
An object increases in mass if it is moving rapidly compared to the observer
Indicate whether the statement is true or false
Which of the following is true of supermassive black holes?
A) They are found only in elliptical galaxies. B) They are not found in Seyfert galaxies. C) They can be triggered into eruptions because of tidal interactions. D) They are not affected by tidal interactions between galaxies.