Show all your work for each part of the question. The parts within the question may not have equal weight.

Figure 1 shows a diagram of a rectangular glider just above a long, horizontal track. The glider is positioned near the right end of the track. The track is placed on and near the left edge of a raised, horizontal surface.
A group of students are given a glider and track. The track is leveled and turned on, so that the glider floats gently on a cushion of air as shown in Figure 
. The manufacturer of the glider/track claims that when the track is turned on, friction between the glider and track is negligible. The students want to determine whether the manufacturer’s claim is correct.

(a) Describe an experimental procedure for collecting data that can be graphed to determine if the manufacturer’s claim is correct. Include any steps necessary to reduce experimental uncertainty. If needed, you may include a simple diagram of the setup with your procedure.

(b) Describe how the data collected in part (a) could be graphed and how that graph would be analyzed to determine whether friction between the track and glider is negligible.

Figure 2 shows a diagram of a rectangular glider just above a long, horizontal track. The glider is positioned near the right end of the track. The track is placed on and near the left edge of a raised, horizontal surface. Attached to the left edge of the horizontal surface is a pulley. A string attached to the left side of the glider extends horizontally to the left, passes over the pulley, and hangs vertically downward. A hanger is attached to the end of the vertical portion of the string. Five washers are placed on the hanger. A sixth washer is placed on the top of the glider.
After performing their procedure, the students conclude that the force of friction between the track and the glider is negligible. In a second experiment, the students are tasked with calculating the mass of a hanger using the glider and track. The students tie the hanger to the glider with a string and place the string over a pulley. The students add six 
 washers to their hanger. The masses of the string and the pulley are negligible compared to the total mass of the washers, hanger, and glider.

The students release the glider – hanger – washer system and measure the acceleration of the glider with a motion sensor. In each of the following trials, the students move one washer from the hanger to the glider and repeat the experiment.

The students correctly derive the following relationship between the mass 
 of the glider with washers, the acceleration 
 of the system, and the total mass 
 of the glider – hanger – washer system: 
 

The data collected by the students is shown in the table.

Mass of glider: 

Mass of each washer: 

Total Mass of glider with Washers,	Acceleration of glider 
(c) The students create a graph with 
 plotted on the vertical axis.

i. Indicate which measured or calculated quantity could be plotted on the horizontal axis to yield a linear graph that could be used to determine the mass of the hanger. Use the blank columns to list any quantities you will graph other than the data provided. The students create a graph with 
 plotted on the vertical axis.

Vertical axis:  
 
 

Horizontal axis: __________

ii. On the grid shown in Figure 
, plot the quantities identified in part (c)(i) that can be used to determine the mass of the hanger. Scale the graph, as appropriate. Clearly label the horizontal axis, including units.

The figure shows the grid labeled Figure 3. The vertical axis is labeled “Total Mass of Cart and Washers, in kilograms,” and the numbers 0 through 3.0 are indicated.
iii. Draw the best-fit-straight line for the data graphed in part (c) (ii).

(d) Calculate an experimental value for the mass of the hanger using the best - fit line that you drew in Figure 3 in part (c)(iii.).