A 0.30-kg mass is suspended on a spring. In equilibrium the mass stretches the spring 2.0 cm ...

A 0.30-kg mass is suspended on a spring. In equilibrium the mass stretches the spring 2.0 cm downward. The mass is then pulled an additional distance of 1.0 cm down and released from rest. Write down its equation of motion.
 
  A) y = (0.01 m) cos (22.1 t)
  B) y = (0.01 m) sin (22.1 t)
  C) y = (0.03 m) cos (22.1 t)
  D) y = (0.03 m) sin (22.1 t)

Question 2

Lenz's Law is a consequence of the law of conservation of
 
  A) mass.
  B) momentum.
  C) electric field.
  D) energy.
  E) charge.

Question 3

In which eon of Earth's history did dinosaurs and mammals first appear?
 
  A) Hadean
  B) Archean
  C) Phanerozoic
  D) Proterozoic

Question 4

The magnetic field near a strong permanent bar magnet might be 500
 
  A) microGauss.
  B) Tesla.
  C) Gauss.
  D) milliGauss.
  E) MT.

Question 5

How many water molecules are there in 36. g of water? Express your answer as a multiple of Avogadro's number NA. (The molecular structure of a water molecule is H2O.)
 
  A) 18. NA
  B) 2.0 NA
  C) 36. NA
  D) 3.0 NA
  E) 0.020 NA