How many waves of 500 nanometers would it take to equal 1 cm?

Answer 1

A 500nm wave has a wave length of 500nm.

The nano- prefix means × 10^-9 → 500 nm = 500 × 10^-9 m

The centi- prefix means × 10^-2 → 1 cm = 1×10^-2 m

→ 1 cm ÷ 500 nm = (1×10^-2 m) ÷ (500×10^-9 m)

= (1/500) × 10^(-2 - -9)

= 0.002 × 10^7

= 2 × 10^4

= 20,000 waves.