Dark energy accounts for what percent of the known energy in the universe?
A) 68 B) 24 C) 8 D) 94
Question 2
Doubling only the mass of a vibrating mass-and-spring system produces what effect on the system's mechanical energy?
A)
increases the energy by a factor of square root of two
B)
increases the energy by a factor of two
C)
increases the energy by a factor of three
D)
increases the energy by a factor of four
E)
produces no change