The average speed of stars relative to the Sun in the solar neighborhood is about 20 km/s. Suppose you discover a star in the solar neighborhood that is moving relative to the Sun at a much higher speed, say, 200 km/s
What kind of orbit does this star probably have around the Milky Way? In what part of the galaxy does it spend most of its time? Explain.
Since stars that are traveling along with us in the disk of the Milky Way move at a velocity relative to us of only about 20 km/sec, we would reason that a star observed to be moving relative to us at a velocity of 200 km/sec was not traveling with us in the disk but was part of some other component of the Milky Way, likely the halo. The orbits of halo stars are not concentrated in the flattened disk but are distributed more like a sphere. So a halo star flying through the disk would appear to us to have the rotational speed of the disk, 200 km/sec.
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A coil is wrapped with 300 turns of wire on the perimeter of a square frame (side length = 20 cm). Each turn has the same area as the frame, and the total resistance of the coil is 1.5 ?. A uniform magnetic field perpendicular to the plane of the coil changes in magnitude at a constant rate from 0.50 T to 0.90 T in 2.0 s. What is the magnitude of the induced emf in the coil while the field is
changing? a. 2.4 V b. 1.6 V c. 3.2 V d. 4.0 V e. 8.4 V
Briefly explain why there is a main sequence on the H-R Diagram
What will be an ideal response?
What celestial line is a product of the Earth's orbit around the Sun?
A) Ecliptic B) Prime Meridian C) Equator D) Galactic Plane E) Analemma
Which type of reaction is 2Cu(NO3)2? 2CuO + 4NO2 + O2?
a. Single-replacement b. Double-replacement c. Combination d. Decomposition