Question

CALCULATIO Show all your work in the space provided below and transfer the results to the tables or results section 1. Calculate the weight, in Newtons, of the mass piled on the sled for lines 2-7 in the first data table. Add the weight of the sled to the weight on the sled to the normal force, N, for lines 1-7 of the first data table. Draw a graph of the data on lines 1-6, plotting "friction force" on the vertical axis and "normal force" on the horizontal axis. Draw a "best-fit" straight line through the data points and determine the slope of this line. Since fk-με N, the data should plot as a straight line through the origin with a slope equal to ux. Enter the value of uu determined from the slope in the space provided in the Results section. 2. 3. From the data on line 7, calculate the coefficient of kinetic friction, μ, when the sled is sliding on its wide runners. Even though the area of contact is doubled, the friction coefficient should be nearly the same as it was previously, providing that friction is independent of area of contact. Enter your computed value of puk in the space provided in the Results section. 4. Enter the normal force corresponding to a load of 400 grams on the sled in the space provided above the data table for procedure 3. Calculate the coefficient of the sta friction μs , for each trial. Average the μ, values and tic calculate the deviation for each t ation. Enter your result in the space provided in the Results section, rial using the average deviation as an estimate of the uncertainty in the average value. Refer to the Introduction for instructions concerning deviation, etc From the data of procedure 4, use Equation (3) on p.3 to compute us for each trial. Calculate the average, the deviation, and the average deviation just as you did in calculation 4 above. Enter your result in the space provided in the Results section. Since procedures 3 and 4 both measured the same thing using different methods, the results should agree. 5. QUESTIONS . Why is it important that the sled be dragged along at a constant speed in procedure 2? LAB 4 -COEFFICIENT OF FRICTION Page 15 DATA Procedure 1: ID letter of sled Weight of sled 233 Procedure 2 Line Mass on Sled, Weight on Sled, Normal Force N, N Friction Force fi,N 2.Bu 시 1.4e | 41le 3.92 200 400 600 | 5.8E le.to 2.2 + . IS = 2.3S 800 81 9.8 S, 72 0, 09 12 08 20 1000 400 Procedure 3: Normal Force, N Trial Static Friction Force, f Deviation 吼. 나6 yo o, 00 G, 00 U, 00 Average 6.36w 6.3N

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