Rubber Band Cart

• In class we launched a cart from a rubber band and measured the velocity with our electric probes.  We learned that the relationship between energy and velocity is that once the energy of the cart is moving the velocity is double the energy creating kinetic energy. 
• Kinetic Energy (K): the energy in motion. 
• The equation for K is K=1/2 mv squared

• After each run with the rubber band cart we wrote down the velocity of the run and the energy from which we collected last lab. 
• Then we created a line graph with our data.

• Did you know that when your on a roller coaster you are experimenting kinetic energy?  As the rollercoaster is using kinetic energy coming up until it reaches the potential energy on top of a rollercoaster.  Once coming down the rollercoaster you experience more kinetic energy of exhillerating fun. 



 

 

Rubber Band Lab

• The Big Question: How can we store energy to do work for us later?  How does the force it takes to stretch  a rubber band depend on the amount by which you stretch it?
• In the lab we decided to stretch a rubber band in different leghnths and measured our results on how much force we were using. 
• The force F is Fs because that is the force to stretch a rubber band. 
• My table's results were:

1cm=0.01m=0.171N
2cm=0.02m=1.109N
3cm=0.03m=1.659N
4cm=0.04m=2.167N
5cm=0.05m=3.197N

• Here is our data graphed on a line graph.  We then had to find out the Fs of our data which was 95n/mx.  In class we also learned the equation to find the elastic potential energy which is the symbol of Us.  To find the Us we had to find the product of 1/2x times the Fs.  Fs=K times x.
• K=the elastic constant and x= the distance stretched.  Because we cannot use Fs we subtitute it for the K times x making the problem Us=1/2Kxsquared. 

Did you know...



• When using a slingshot there is also elastic potential energy used.  When we pull the object back with the rubber band we are holding energy. It is not until we release the object that we are using the energy from the rubberband. 

MichaelWheatonPhysics

Simple Machines

• In class we learned how simple machines are manipulated by force.  First we made a pully machine and calculated the amount of force it took to lift the weight from 10cm.  We also had to measure the string we had to pull to use the pulley system.  Our goal was to lift a 200g weight with only 0.5 N of force. 
• Had four tries for our experiment.

1. force: 1.5N, string: .13m
2. force: 1.5N, string: .29m
3. force:1.3N, string: .28m
4. force: .53N, string: .28m

• Our next objective was to graph our data.  Since the project was to only graph one bar we had to round our data.  We had two graphs; one with the pulley and one without the pulley system.  Then we put the equation A=(N)(m).  We also learned that half the force is double the distance. 

Did you Know...

• As you move something onto a cart you are using a simple machine.  In what we learned using half the force you can double the distance.  Instead of bringing the object and then lifting it in the truck we are moving on the ramp which is less the force.  In doing so, the ramp also creates double the distance.