Rubber Band Lab

This week we used a rubber band and a force probe to find how we can store energy to do work for us later. We experimented with two different trails to find force (Fs) in terms of distance stretched (X). For the first trial, we used a single loop and stretched the rubber band to various lengths, while recording the force needed with the electronic force probe. Next, we had a double loop on the rubber band and repeated the experiment.

Units used:
m = metersN = newtons (force)K = elastic constantFs = force needed to stretchX = distance stretchedUs = elastic potential energy

Single loop data:
1 cm = .285 N
2 cm = .728 N
3 cm = 1.434 N
4 cm = 1.85 N
5 cm = 2.797 N
Double loop data:
1 cm = 2.31 N
2 cm = 3.866 N
3 cm = 6.22 N
4 cm = 8.32 N
5 cm = 11.72 N

In our graph we used  y=mx+b. In our graph force was on the y-axis and distance was on the x-axis, so we knew that the y variable would become Fs (force stretched) and the x variable would become X (distance stretched). We then found the slope of the line, which was 60 n/m. This was also the elastic constant (K). Because b=0, we derived the equation Fs=KX.

Real World Connection: 

The greater the distance the bow and arrow is stretched, then the greater the force needed to stretch, and the greater the potential energy. If you use a lot of force to pull the object back, the farther the object will go.

Pyramid Lab

In class last week, we did the pyramid lab. We pulled weights up a ramp to a specific height. After each trial, we changed the length of the ramp. The height remained the same. We used the lab probe to figure out how much force was required to pull the weights up the various lengths of the ramp.Our group found out that it is impossible to decrease the force required to move something without increasing the distance required to do it. 




While the force and distance changed, the area of all the graphs were the same. This is because the height that the weight is being lifted is constant and therefore, the amount of work or energy required for the task is constant as well. The ramp only manipulates the levels of distance and force required.



Simple machines are everywhere in our day today lives. For homework, we had to watch a theory that showed the Egyptians creating simple machines to build their pyramids. To me, it seems like people prefer less force over shorter distances. We would rather walk up a long ramp than a short flight of steps. It seems that you can find the formula "work=fd" in almost every motion of our lives.

Pulley Lab

For our pulley assignment, we created 3 different pulleys. My group created a simple pulley, a two-string pulley, and a four-string pulley. For each pulley, we measured a 200g weight and measured the force required to hold the mass steady. It took 20 cm of string to raise the weight 10 cm, which shows the increased distance and decrease of force being used.

In the picture, it shows the force required to hold the 200 g mass steady, and the string required to move the 200 g.

                                                                                  

The area all equaled .01 m/n which showed their inverse relationship. Force x Distance together are constant. Also, F x D = Work, and newtons x mass = joules. 

Simple machines have an impact on our lives because it makes it easier for us. Objects such as the pulley and hammer makes work require less energy because of the less distance required to complete the job.

Force Vs. Mass

In the Force vs. Mass lab, we measured the different amounts of force caused by different weights. The force was measure in Newtons while the mass was in grams and kilograms. In the picture, the force (dependent variable) is on the y-axis, while the mass (independent variable) is on the x-axis. As my group calculated the line graph with the information we had, we noticed a consistent upward trend, as the mass increases, the force increases. For example, the heavier an object, the more force is required to push the object. We plugged in our calculations to find the slope of the experiment, using the equation "y=mx+b." After doing the work, we concluded that Force is equal to 10x the amount of mass. In the equation, 1 kg = 10 newtons.