Category: Physics

Baffling Bungee

This week’s science challenge requires the principals of physics and chemistry to solve.

Diagram of Baffling Bungee Jump.

Bob the bungee jumper goes bungee jumping over water on a cord made out of C5H8. The thickness of the rope is 3 centimetres. It’s natural length, the length it will have if not acted on by a force, is 1 metre. Bob starts the jump with a velocity vector with a magnitude of 1 metre per second and an angle of 45°. The lowest point of the jump is 1 metre above the water. Afterwards, the cord pulls Bob up to a stable position higher above the water. The challenge is to calculate the elasticity of the rope to figure out exactly how high.

Solution

Spinning Stick

You will need an understanding of physics and calculus to solve this science challenge.

Diagram of the Spinning Stick.

A uniform stick with length 2 metres rotates at a speed of 1 rotation per minute on a flat plane. It comes into contact with a stationary ball. The stick is kept spinning about it’s origin at the exact same speed by a motor. The ball is only affected by the stick’s rotation, and does not experience friction or roll over the stick. The ball will eventually escape the stick from centrifugal force. The challenge is to find the velocity of the ball when it is flung off of the stick.

Solution