# Calculate the frequency of red light of wavelength

1. May 11, 2008

### looi76

1. The problem statement, all variables and given/known data
The speed of light is $$3 \times 10^8 ms^{-1}$$. Calculate the frequency of red light of wavelength $$6.5 \times 10^{-7} m$$.

2. Relevant equations
$$v = f\lambda$$
$$f = \frac{v}{\lambda}$$

3. The attempt at a solution

$$v = 3 \times 10^8 \ ms^{-1}$$
$$\lambda = 6.5 \times 10^{-7} \ m$$

$$f = \frac{3 \times 10^8 }{6.5 \times 10^{-7} }$$

$$f = 4.6 \times 10^{14} Hz$$
$$f = 450 THz$$

Everything looked fine until $4.6 \times 10^{14}$ became $450 \times 10^{12}$.