Shorter passages
1 Apparent depth
The short passages below are attempts to describe the method used to estimate the apparent depth (length) of a 50x25x25 cm glass fish tank, full of water. Many people looked into the square 25x25 cm end of the tank. The used both eyes and put their faces close to the end wall. They each reached down the side of the tank and marked where they judged the end of the tank to be. They were unable to see their hand as they did this, because of total internal reflection from the sides of the tank. When thirty attempts had been made, the estimated lengths were entered into Logger Pro and a histogram was plotted. The mean of the normal distribution (the apparent length of the tank) was found to be 38 cm. The actual length was 50 cm.
a A fish tank was filled with water. Participants marked on the side of the tank where they estimated the end to be. Measurements were taken and a histogram was plotted. The top of the curve was the average distance perceived.
The explanation is short on information.
In the words of Professor Walls, to "Put in more words."
b A large fish tank full of water was placed in back of room. Students were asked to look into one end of the fish and notice the mirror image that was created by total internal refraction. Students were then asked to take a marker and mark while looking through the end of the fish tank, where they thought the end of the fish tank to be. This procedure was repeated twice, or once for each side. Measurements were gathered by Dr Jacobs using a meter stick. The data collected was placed into the Logger Pro software and a graph was drawn based on the data. The average length was about 37 cm.
The passage fails for lack of precision and the inclusion of irrelevant information: where the tank was and who measured the apparent lengths. When is a graph not based on the data entered?!
Editing and proof reading (reflection not refraction) would improve it.
c In this experiment the total internal reflection was investigated. With opaque water in a rectangular water tank, laser was beamed through the water tank and its refraction as observed. When the laser was beamed in from one side of the water in certain degree, the beam did not go through the water tank and it was reflected at 90 degree. In addition when the water tank was viewed with naked eyes from one side of the tank, the other two sides of water tank were worked as mirrors.
Do not begin with " In this experiment .... or similar constructions. The passage fails because of a lack of precision, and because the point of the exercise was missed. The measurements were about apparent length. The total internal reflection that made the sides of the tank appear to be mirrors was incidental. Note: ... the water was transparent, not opaque. Editing will not rescue this passage.
Make a list of the important points and start again.
d A rectangular fish tank measured 50 cm long and 25 cm wide is filled with water. The end of the tank would appear by looking into one end of the tank to another. A marker is used to mark where the end of the tank appears to us at (this is done to both ends of the tank). The meter stick is used to measure from the end of the tank to where the marks are. Then the data is recorded into Logger Pro to make a histogram. The average, in the middle of the tallest bar in this experiment is 38.0 cm.
The passage fails because of improper control of tense. A past passive construction using was and were is preferred. It also fails from a lack of precision and clarity.
Rewrite in the past passive with more specific descriptions of the procedures.
2
In order to create a model for a sphere falling through one or two fluids in different sized containers, the applicable forces must be summed and the resulting equations manipulated in order to allow us to make accurate predictions about the physical situation. Our goal is to understand how the motion of a sphere is affected by all of these phenomena. In this paper, we examine previous studies on various topics involving objects falling through fluids. We then develop the theory and governing equations involved in the modeling of each type of situation previously mentioned. Finally, we compare our model with experimental data in order to test the accuracy of our theory.
Graduate students are writing about their work. They have not had the services of a competent editor.
Compare the above with this reduced version ...
When a sphere falls in water without rotation there are three relevant forces: weight, drag and buoyancy. The literature is reviewed and a model is developed, based on existing theory. Data is collected to test the model.
3 Vortex rings in air
In this experiment, the video of an air vortex traveling through air over a distance (4 meters) was analyzed using Logger Pro to find out the velocity of vortex after certain distances traveled. The impulses of the vortices at different distances were probed separately and used to calculate inferred mass of the vortices.
The meaning is unclear. The passage has apparently not been proof-read.
A rewrite might go like this ...
A vortex ring formed by an air cannon was fired at a force plate made with a sheet of plastic and four force probes. The velocity of impact (v) was plotted against the impulse measured on the plate (mv) to find the mass of the vortex. Data was collected at different distances. Graph 1 is a plot of vortex mass against the distance from the canon.
4 The exercises mentioned in the lab were physically done with the help of the computer program Logger Pro. With the help of a Vernier motion detector and a Vernier dual range force probe obtaining values to plot graphs with was very easy. Data was collected in two ways as mentioned before in the control of variables. It was collected by pushing the trolley from one side of the room and then from the other. From each side or the room the values were recorded at least five times. The following graph is recorded from one of the sides of the room. The integral of the graph is the friction force applied to the trolley.
A trolley and container of water were pushed with a force probe to verify two principles. Work done equals KE gained, and impulse applied equals the change in momentum. This passage was a first attempt.
Identify the anthropomorphic fallacy, zero statements, and redundant sentences. The passage requires a complete rewrite.
5 Also since the environment was not in a contained setting the air current in the room fluctuated the consistence of the flame therefore hindering the experimental results.
What is he trying to say?
6 Normally, when an airplane travels through the air, the wings push the air in front of it out of the way. However, the signal for air to move out of the wing's way can only travel at the speed of sound (in air). So if the airplane is traveling faster than the speed of sound, the air cannot move out of the way. This creates a sudden, intense pressure drop that moves away from the wing at the speed of sound, just like the wake behind a boat. It is the sound created by the pressure change that we hear after the airplane has passed over our heads.
This passage is from a graduate student at UC Berkeley. It could be improved by explaining how the wake of a boat is created and then applying the same principle to sound. It would be helpful to mention the reduced angle of the wake as the speed of the boat increases.
Rewrite the passage, without the zero words and the "signal" comment. Take care, the physics not easy to explain in a few words.