Rubber Band Inquiry Lab

This week in class we explored the way that energy is stored in objects using a metal ramp, rubber band, and force probe.

The purpose of this lab was to find how energy can be stored for later and to discover the relationship between a rubber band's force and how far it is stretched.

For the first part of this lab,  we measured the force of the rubber band when we stretched it to a  specific distance (1cm, 2cm, 3cm, 4cm, and 5cm). We noticed that the farther the rubber band was stretched, the more the force increased. Then, we repeated the trials after doubling the rubber band, causing the force to increase even more. If we stretch a rubber band, the bonds are storing energy. The more we pull, the more energy we have.Rubber can store more energy than material such as wood because they have more stretchy bonds. The stored energy is then released if we let the rubber band go.

The trials that we completed showed us that it takes more force to stretch a rubber band farther. In other words, the farther the distance the greater the force.

We concluded that the force is the ELASTIC SPRING FORCE. This was when we lerned a new formula (YAY!)

SPRING FORCE EQUATION:

Fs =K*X (similar to y=mx+b)X= stretch distanceFs=spring force 

K=slope or "k value" (see below)

IV=X (distance)

DV=Y (force)

Slope of x and Fs is called the "k value" or elastic spring constant. The "k value" is different for every rubber band (some atoms have tighter bonds than others) just like "g" (Earth's gravitational force) is different for every planet


Potential energy is stored energy*

Real World Connection:

Bungee jumping is quite similar to the lab that we performed this week. As the person jumps and falls the cable that connects them to life is pulled more and more by the weight of the person. The more force that is applied to the cable, the more energy is stored in the bonds. When the cable reaches it's maximum "k" value, or when the rubber bands is stretched as far as it can go, the energy is released, causing the bungee jumper to shoot back up into the air like a sling-shot.