A star remains on the main sequence for a time span equal to _____ of its total existence as an energy-generating star
A) 90 percent
B) 40 percent
C) 15 percent
D) 55 percent
A
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A +2.0-nC point charge is placed at one corner of a square (1.5 m on a side), and a ?3.0-nC charge is placed on a corner diagonally away from the first charge. What is the magnitude of the electric field at either of the two unoccupied corners?
a. 20 N/C b. 14 N/C c. 4.0 N/C d. 12 N/C e. 8.0 N/C
Inside a house, stepping on a tile floor barefooted may feel almost cold, but stepping on carpet in an adjacent room feels comfortably warm. Why is this?
a. It's because the tile is below room temperature while the carpet is at room temperature. b. It's because the tile is at room temperature while carpet is normally warmer. c. It's because the thermal conductivity of tile is less than that of carpet. d. It's because the thermal conductivity of carpet is less than that of tile.
A gamma-ray burster emits a quantity of energy similar to that emitted in a _________
Fill in the blank(s) with correct word
Flashes from unseen lightning are called ______________
Fill in the blank(s) with correct word