Mechanical Advantage talk by David

This afternoon, David (Breanna's Dad) was kind enough to come and talk to us about some of the forces involved in rescuing rock climbers. He is very knowledgeable and has been rock climbing for over 35 years.

David talked to us about Mechanical Advantage. He started by showing us what it would be like with no mechanical advantage - a simple tug-of-war. He then changed the ropes so that 1 person could 'out tug' 2 people. He kept going so that 6 people were able to tug against 1 person and the single person was still able to win. By looping more ropes around more pulleys the mechanical advantage increased. This means that if someone was stuck at the bottom of a cliff, and you knew how to set up the ropes correctly, a small person could pull up a big person up to safety.

Some of this is a bit tricky to understand but if you want to look further into this, have a look at the following websites:

https://www.youtube.com/watch?v=9T7tGosXM58 - This is a great YouTube video that explains the concept in child friendly language

http://www.ropebook.com/information/pulley-systems - This has some great images and explanations of 1:1 - 6:1 pulley systems

Some of us were also able to experience what happens when a rope slips between our hands - Friction. OUCH! Thanks for taking the time David, to help us understand this.