# College Physics 2.7 – The rate at which the North American and European continents are moving apart

## Solution:

We know that the formula for velocity is

$\displaystyle \text{velocity}=\frac{\text{displacement}}{\text{time}}$

If we rearrange the formula and solve for time, we come up with

$\displaystyle \text{time}=\frac{\text{displacement}}{\text{velocity}}$

Substituting the given values,

$\displaystyle \Delta \text{t}=\frac{500\:\text{km}}{3\:\text{cm/year}}$

$\displaystyle =\frac{5\times 10^5\text{ m}}{3\:\text{cm/year}}\times \frac{100\:\text{cm}}{1\:\text{m}}$

$\displaystyle =1.67\times 10^7\text{years}$

Therefore, the time it will take is about $\displaystyle 1.67\times 10^{7}\ \text{years}$.