The time of an echo

A girl claps at different distances from a wall. You will make the program find the time of each echo, list the distances at which she hears a separate echo, and find how the echo time changes on a hot day. Then it draws the echo time against the distance.

The idea. The sound goes to the wall and back: $t = \dfrac{2d}{v}$. A separate echo needs at least $0.1\ \text{s}$.

Your tasks.

1. Inside the loop, work out t, the echo time for each distance, in seconds (with $v = 340\ \text{m/s}$).
2. Make separate, the list of distances whose echo time is $0.1\ \text{s}$ or more.
3. Find t_hot, the echo time from $100\ \text{m}$ when the air is at $35\ ^\circ\text{C}$, using $v = 331 + 0.6T$.