Our best measurements from Earth indicate that the star system Alpha Centauri is 4.2 light-years away. Suppose some of our astronauts traveled there at a speed v = 0.90c. What would the astronauts measure as the distance to Alpha Centauri?
a. 1.3 lightyears
c. 1.8 lightyears
b. 4.0 lightyears
d. 2.7 lightyears
C
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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
A solid sphere, a solid cylinder, and a hoop each have the same mass and radius. If they are spinning at the same angular velocity, which one has the greatest angular momentum?
a. the sphere b. the cylinder c. the hoop d. They all have the same angular momentum.
Graphical Analysis: Which of the following graphs represent an object having zero acceleration?
A. only graph a B. only graph b C. graphs a and b D. graphs b and c E. graphs c and d
A barge is 10.0 m wide and 60.0 m long and has vertical sides. It is floating in fresh water. A load of 6.00 MN is placed on the barge. How much does its hull sink into the water?
A) 5.00 m B) 7.21 m C) 10.2 cm D) 10.0 m E) 1.02 m