## Saturday, May 21, 2011

### Two Months in the Temple (Part 2)

Willie's Wheel of Fortune

The Scene: Willie is in a cage and being lowered into the fire pit by Indy (under a spell)

The Question: It seems as though when Willie is being pulled back out of the fire pit, she must be moving faster (because it takes so much less time) than when she is being lowered. Does this make sense if Indy is the only person pulling Willie (and her cage) back up?

Game Plan: We are scaling the wheel (using Ford's height and Logger Pro) and figuring out how long one rotation of the wheel takes when Willie is being lowered (to find her velocity) using kinematics. We will do the same thing while she is being pulled back up. We will compare the two velocities and see if they are reasonable speeds for Willie to be traveling at to determine whether or not movie magic or real physics was used. Kinematics will be the best route because we need to find velocity and Willie's displacement on each trip.

Indiana Jones and the Raft of Doom

The Scene: The scene begins after Indy and co. jump out of the plan on a raft and land on the side of a snowy mountain.  The group slides down the mountain on the snow, and then slides on the dirt.  They continue to slide on the dirt until they slide off the cliff.

The Question: The goal is to find the coefficient of kinetic friction for the snow and dirt as the raft flies over it. If we have time, we will find the minimum coefficient of kinetic friction needed to stop Indy and friends from falling off the cliff.

The Game Plan: From the video, we measured positions and times to get velocity of the raft, and we will use kinematics, a force diagram, and a net force equation to determine the coefficient of kinetic friction.

It's Gotta Be the Shoes!

The Scene: Mine cart scene where Indy uses his foot as a brake to stop the cart

The Question: We want to find whether or not Indiana Jones’ leather soled shoes would catch on fire if he used his shoe as a brake.

The Game Plan: We need to find the initial velocity, how fast the wheels are rotating per minute via initial velocity, the μk, the mass of Indy's cart, and the angle of Indy's shoe compared to the ground.  From the Fnets and work energy theorems, we shall find the force of friction, then using the specific heat equation, we will find the minimum energy needed for the shoes to catch fire.  Then, we will compare the energy converted to heat between Indy's shoes and the wheel to the minimum energy needed.

Don't Drag Me Down

The Scene: The raft falls from the cliff!