To calculate the masses of stars in a binary system, we must measure their
A) spectral types and distance from Earth.
B) absolute magnitudes and luminosities.
C) luminosities and distance from Earth.
D) orbital period and average orbital distance.
D
You might also like to view...
A 0.140-kg baseball is dropped from rest from a height of 2.20 m above the ground and experiences negligible air resistance as it falls. It rebounds to a height of 1.60 m. What change in the ball's momentum occurs as it rebounds from the ground?
A) 0.117 kg ? m/s upwards B) 0.117 kg ? m/s downwards C) 1.70 kg ? m/s upwards D) 0.350 kg ? m/s upwards E) 0.350 kg ? m/s downwards
A resistor and an inductor are connected in series to a battery. The battery is suddenly removed from the circuit and replaced by a wire to complete the circuit
The time constant for of the new circuit represents the time required for the current to decrease to A) 75% of the original value. B) 25% of the original value. C) 63% of the original value. D) 37% of the original value. E) zero.
On March 21, the Moon is in its first-quarter phase. An observer who sees this Moon on his or her meridian at this time
a. cannot see the Sun. b. sees the Sun setting. c. sees the Sun rising. d. none of these
Because of Heisenberg's Uncertainty Principle, the velocity of a particle is known least precisely when the length of the wave packet representing the particle is
a. < 10-15 m. b. < 10-10 m. c. of the order of 1.00 m. d. >10 m. e. the length of a plane wave (infinite)