Today we performed an experiment in class which involved using a pulley and an electric motor (the same electric motor used in the robot car experiment).  We had the motor operating at different speeds and used various quantities of weight, then we would check the speed of the crane and record the differences in timing. The pulley just had a string and metal hook attached, the hook was about 4 inches long.  The basis of this experiment was to gain a better understanding of energy, force and mass against gravity. We then used our recorded data as support for believing the higher the mass of an object requires more force to lift it.

Below is a chart where in trials 1-3 the power was held constant, in trials 3-6 the weight is held constant.  My group’s graphs would not upload to word press which is unfortunately why only the chart is included here.  When the speed was held constant, the slope of the line was negative. However, when the weight was constant there was a positive correlation and the slope was positive. For the first 3 trials, the average acceleration with the power level remaining at 75 was about 42.5 RPM/s  (rounded up). The average acceleration for when the mass remained the same at .18 kg is 44.132 RPM/s.

If you have any questions or comments feel free to leave them.

For those who may be unaware slick water hydraulic fracturing (Hydrofracking), is a newer methodology in natural gas extraction. This process has made mining for natural gas in dense shale underground possible [1]. Before I get into whether or not Hydrofracking is good or bad for the people living near where companies are preforming this process, I want to explain how Hydrofracking is preformed and how it differs from older methods of extracting natural gas from the Earth. 

In a nut shell this is essentially how Hydrofracking works. A drilling company builds a drill site in the location they choose. Right now states such as Pennsylvania, Ohio, and New York (among others) are popular [3]. Setting up their drill site involves removing trees, building an access road and rig, and making room for the appropriate equipment, vehicles, and chemicals that they would need to undergo the process [1]. Once the site is set up they drill into the ground downward and eventually horizontally up to about 8,000 feet in each direction [1].  Once the well bore (hole) has been drilled they inject about 6-8 million gallons of freshwater (per fracking), sand and other chemical-based additives like: diesel fuel, biocides, benzene and hydrochloric acid into the ground through the well bore [1]. This props open the fissures caused by the well bore to allow the gas to seep through the pores in the shale, which eventually makes its way to the well bore and then they are able to extract the gas [1]. If this seems a little confusing below is a picture to help.

Hydrofracking has a few differences from conventional natural gas drilling. Hydrofracking uses much more water than conventional drilling, it uses “slick water” which is a mixture that is pumped into the shale to fracture the rock and release the gas [1]. Additionally, there is a potential for toxicity and its long-term impacts.

Although Hydrofracking is a more economically efficient it has downsides which could gravely affect our habitat and water supply. Some of the negative impacts of this are surface and subterranean damage, groundwater and surface water contamination and habitat/species damage [2]. The chemicals used like benzene are very toxic even in the parts per trillion [1]. This is important because if these chemicals were to integrate with the water table, under which is the shale with a layer of bedrock in between, people’s drinking water could be affected. Unfortunately disclosure by the companies preforming Hydrofracking of what chemicals and in what amounts they use them are very vague, they tend to say they only use them in “small amounts” not revealing the actual quantitative measures used in the process

Sources:

[1]- http://www.peacecouncil.net/NOON/hydrofrac/HdryoFrac2.htm 

[2]- http://www.newser.com/story/112950/hydrofrackings-ugly-secret-from-gas-wells-bad-water.html

[3]- http://www.huffingtonpost.com/paul-gallay/fracking-environment_b_1186998.html

My class and I recently completed a lego robot car experiment. In the first part of the experiment we had to build the car by following instructions online and then we put a electronic battery attached to a small computer on the car. This small computer(car) had USB cords attached to itself from a computer. We used the computer to program the robot car with commands so it would be able to move. The purpose of this experiment was to test the velocity, acceleration and distance traveled by the car, while making 1 complete revolution, or circle.  The robot car below is a close resemblance as to the one we used in class.

For the second part of the lab experiment we were supposed to make the robot do 1 complete revolution.  To accurately do this we had to measure the distance that the wheels traveled, speed at which the car traveled, measure the diameter of the wheel and compute the circumference, record the number of degrees that the wheel rotated in comparison to the number of turns the wheel committed, record the time it took for the wheels to turn, and in order to make the car do a perfect circle inside the circumference of 2 feet we did multiple attempts with the motors at different power levels.

The results are as follows for our final attempt:

Degrees of rotation for wheel one: 471

Degrees of rotation for wheel two: 472

Number of wheel turns: 1.30833

Distance traveled: .24649 meters

Velocity: .08216 M/S

Time it took: 3 seconds

Power level of both motors: 25

Circumference: .1884

The results to the