A typical protostar may be several thousand times more luminous than the Sun. What is the source of this energy?
A) Chemical combustion of hydrocarbons
B) Nuclear fusion in its core
C) From the release of gravitational energy as the protostar continues to shrink
D) The ionization of the gas as it heats up
E) From nearby hot stars or supernovae that have initiated the star formation process
C
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Exhibit 17-3Four wave functions are given below. I.y(x, t) = 5sin(4x- 20t + 4) II.y(x, t) = 5sin(3x- 12t + 5) III.y(x, t) = 5cos(4x + 24t + 6) IV.y(x, t) = 14cos(2x- 8t + 3)Use this exhibit to answer the following question(s). Refer to Exhibit 17-3. Rank the wave functions in order of the magnitude of the wavelengths, from least to greatest.
A. IV, II, I, III B. IV, I, II, III C. I, II, III, IV D. IV, II, III = I E. I = III, II, IV
Resistance and Resistivity: A 1.0-m length of nichrome wire has a radius of 0.50 mm and a resistivity of 1.0 × 10-6 ? ? m. When this wire carries a current of 0.50 A, what is the voltage across its ends?
A. 0.0030 V B. 0.32 V C. 0.64 V D. 1.6 V
Suppose we look at two distant galaxies: Galaxy 1 is twice as far away as Galaxy 2. In that case
A) we are seeing Galaxy 1 as it looked at an earlier time in the history of the universe than Galaxy 2. B) we can't say anything about these galaxies except for their distances. C) we are seeing Galaxy 1 as it looked at a later time in the history of the universe than Galaxy 2.
How does the slope of the graph in Procedure 1 compare with the average value of C d?