moldybluecheesecurds 2

Showing posts with label lift. Show all posts
Showing posts with label lift. Show all posts

Friday, May 25, 2007

Why we need more physics education

We got a canoe last weekend. A nice find via Craigslist, it even included some lifejackets (aka PFDs), paddles, and a little trailer. K drove 3 hours round-trip to pick it up and we're excited to have our own canoe at last.

Then came the storage issue. The garage door eliminated jff's brilliant plan to hang the canoe over the car, allowing for quick loading/unloading. Canoe must hang sideways. Okay, then we have to clear the rafters of all the accumulated junk from previous owners (hey, nice golf clubs!). Now jff applies his high school physics and gets a couple pulleys. Gee, for some reason, lifting a 60-pound canoe with a thin rope isn't as easy as you would think.

Jff goes advanced - looks up pulleys on Wikipedia. Purchases additional pulleys and constructs a basic "block and tackle" (and slicing thumb with utility knife). In theory, we now only need to exert 30 pounds of force to lift the canoe. (see image)

After a ferocious battle that succeeding in lifting the canoe to the garage ceiling (30 pounds, my ass!), team Canoe Lift could not cleat the rope without dropping the canoe. This failure despite jff wrapping himself in the lift rope like a mummy whilst K attempted to tie it down.

So, those who get physics - help! What's wrong with the pulley system? Is the solution more pulleys (see image below - bonus pulleys in red)? Counterweights? A patch of grass and a tarp?