Notes

find: Coefficient of friction kinetic (μk)

Formulas:
Ff=μ*Fn
Fn=mg
g=9.80
a= ΣF/m
a={[mw (mass of weights)-m]*g}/mw+m

Steps:
1.) Wear Safety Glasses
2.) Attach string to a thumbtack. Attach thumbtack to wood block.
3.)T1=1.86 m/s/s; T2=1.67 m/s/s; T3=1.77 m/s/s; T(ave)=1.767 m/s/s;
4.)

Procedure:
0.) Wear your safety glasses
1.) Gather materials (See materials list)
2.) Lay aluminum track on a level surface.
3.) Attach pulley to the start of the track(confirm that it is parallel to the track)
4.) Measure the wood board (to find mass)
5.) Attach thumbtack and string to wooden board.
6.) Lay the opposite end of the string onto the pulley. Attach weight(s) to the end of the string
7.) Set up motion sensors at the far end of the track (adjust to find acceleration) *There must be a 15 cm distance from the wooden board to the motion sensor.
8.) *To start a trial: attach your chosen weight and start the motion sensor. Release your grip on the wooden board and let it slide. Record the motion sensor data (acceleration) and repeat if required (three times total)*
9.) *Record where the acceleration was constant/ the straight line on the graph provided by the motion detector. Find the mean (average) of the segment).
10.) REPEAT steps 8-9(Three times total)
11.) Remember to convert grams to kilograms before doing any calculations.
12.) Use Newton's 2nd law to determine what mu is. (assume that the acceleration due to gravity is 9.8 m/s/s)
13.) Refer to the equation: the sum of all forces of the system is equal to the mass total times the acceleration.
14.) Therefore, acceleration is equal to the sum of all forces divided by the total mass
15.) The force of friction will move against the mass of the board, therefore it must be negative in the system. The force of friction is equal to coefficient of kinetic friction (mu) times the normal force of the mass, which is just the mass of board times the force of gravity but positive.
16.) The system will move positively in the direction where mass 2 (the weight) is going, therefore it is positive mass of weight times the force of gravity. Therefore, the sum of all forces in the system is equal to a negative force of friction + (mass of weight times the force of gravity).
17.) Therefore the acceleration is due to the sum of all forces of the system divided by the total mass of the system (mass of board + mass of weight).
18.) Rewrite the equation to solve for mu.
19.) Plug in for all variables and solve for mu.
20.) Answer should be around 0.3