Hubble’s parameter

Metric System: The volume of a 10-mL test tube is equivalent to which one of the following quantities?

A. 0.01 L B. 0.001 kL C. 0.1 L D. 1 × 10-6 L E. 0.001 ML

Imagine that it turns out that dark matter (not dark energy) is made up of an unstable form of matter that decays into photons or other forms of energy about 50 billion years from now

Based on current understanding, how would that affect the universe at that time? A) Stars would cease to exist when the dark matter is gone. B) Planetary systems would expand and disperse. C) The galaxies in clusters would begin to fly apart. D) The universe would cease its expansion.

Suppose you measure the density (mass per volume) of an object moving by you at very high speed. How will its density compare to the density it would have at rest in your reference frame?

A) Its density would be lower. B) Its density would be higher. C) Its density would be the same. D) There is no way to know, because relativity doesn't tell us anything about density.

In a head-on automobile collision, a person's momentum could be reduced from 2000 kg m/s to zero in just 0.1 s. If this occurs, the average force exerted to stop the person is

A. 2,000 N. B. 20,000 N. C. 200 N. D. This can't be answered without knowing the person's mass