1. A 68 kg driver gets into an empty taptap to start the day's work. The springs compress 2.2×10−2 m. What is the effective spring constant of the spring system in the taptap?

Enter the spring constant numerically in newtons per meter using two significant figures.

2. Which phenomenon provides the BEST evidence that light has a wave nature?

a.     reflection of light from a mirror

b.     diffraction of light passing through a narrow opening

c.      absorption of light by a black sheet of paper

d.     emission of light from an energy-level transition in a hydrogen atom