Zip lines: tensions and torques

This year's Boo on Ballard had a Physics lesson built right in!! They had a zip line set up just begging to be analyzed in terms of forces, torques and spring constants!

Check out the video below: 

So, can you draw a diagram to show the tensions involved on a zip line?
What can you say about the torque applied by the hydraulic lifts in relation to the tension of the cables?
Think about the spring at the end. What considerations need to be made to make this safe?

Looking for some cash? Try science & engineering

Read the article linked below (they are the source of the images), but basically, science and engineering make up the top paying jobs out of all majors (top chart) and bachelor's degrees (bottom chart). Definitely worth knowing!

http://www.npr.org/blogs/money/2013/10/22/239698749/the-most-and-least-lucrative-college-majors-in-2-graphs?ft=1&f=

Whales and thermodynamics

So, you think whales take in water through their mouths and spew it out their blow holes? Wrong!!!
Check out this article on whales:
http://www.todayifoundout.com/index.php/2013/10/whales-dont-spray-water-blowholes/

This is a great example of thermodynamics at work. The air in the whale is both warm (due to the body heat of the whale) and is being compressed before being released (it has to push out the air - I imagine it has a diaphragm that causes additional pressure for expelling air). Warm air can hold a lot of water vapor. When the warm air is released, it mixes with cool air, which cannot hold as much water vapor, forming drops. It also reduces in pressure, which further cools the air as it expands.

The water drops in the spout from the whale are similar to when we breathe out in cold winter air and see clouds form, only theirs have more and larger droplets form.