Monday, October 1, 2012

Rubber Band Cart Launcher




Big Question:
"How are energy and velocity related?"
If the amount of energy increases, then the velocity will also increase. 

Purpose: 
The purpose of performing this lab was to be able to identify the relationship between energy and velocity using the cart and rubber bands. 

Lab: 
In this lab we stretched the rubber band back starting with 1 cm and going up to 5 cm. We put the cart through two trials of each measurement and used the photo gate to measure the carts velocity( in m/s). We then took our velocity recordings for each separate measurement and we averaged them, and then squared the average. From there we were able to graph and find a best fit line. 


Key Information:
E=1/2 mass velocity squared
E=0.2v^2
The formula for kinetic energy is K= 1/2mv^2
We learned that energy is always transferred form one place to another. 
The energy is stored in the rubber band. Without the energy coming from the rubber band the cart would not be pushed forward.  

Real World Connection:
A real world connection to the concepts we learned in class is a slingshot. The more you pull it back the  the object will fly out with more velocity.This video shows a human sling shot that shoots the kids in the air and into the water:  http://www.youtube.com/watch?v=ShFAeNdiEiA