Leavitt's law is a relationship between
A) a Cepheid variable star's period and luminosity.
B) a galaxy's distance and recession speed.
C) a galaxy's distance and redshift.
D) a main-sequence star's color and luminosity.
A) a Cepheid variable star's period and luminosity.
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Light is refracted through a diamond. If the angle of incidence is 30°, and the angle of refraction is 12°, what is the index of refraction?
a. 1.3 b. 2.4 c. 2.6 d. 1.8 e. 0.4
Two objects with indices of refraction n1 and n2 are placed in the same liquid substance and have their critical angles measured. If experiment shows that ?c1 > ?c2, then it must also be true that
1. n1 < n2. 2. n1 > n2. 3. n1 = n2. 4.more must be known to determine the relationship between n1 and n2.
Plants are considered part of the ?
What will be an ideal response?
A long solenoid (1500 turns/m) carries a current of 20 mA and has an inside diameter of 4.0 cm. A long wire carries a current of 2.0 A along the axis of the solenoid. What is the magnitude of the magnetic field at a point that is inside the solenoid and 1.0 cm from the wire?
a. 78 ?T b. 55 ?T c. 48 ?T d. 68 ?T e. 2.0 ?T