Algebraic Expressions

When a thunder and lightning storm approaches, you can calculate approximately how far away the storm is (in miles) by counting the time between seeing the lightning and then hearing the thunder. The table below shows the relationship between the seconds counted and how far away the storm is.

If you are $10$ miles away from a storm, how many seconds would you expect to count between seeing the lightning and hearing the thunder?

Orb spiders create webs that are nearly circular, with every new row almost exactly the same distance away from the previous one. As an orb spider spins its web, the number of segments increases. As the orb spider adds more segments, the radius of the area where prey can be caught increases. The distance between any two rows is roughly $2 \mathrm{cm}$. If the radius of the web is $30 \mathrm{cm}$, how many rows are there?

Orb spiders create webs that are nearly circular, with every new row almost exactly the same distance away from the previous one. As an orb spider spins its web, the number of segments increases. As the orb spider adds more segments, the radius of the area where prey can be caught increases. The distance between any two rows is roughly $2 \mathrm{cm}$. If there are $11$ rows, radius of the web is $\mathrm{k} \mathrm{cm}$. Find the value of $\mathrm{k}$.