Data Table 4: Location of Masses for Balancing Three Masses Data Table 1: Mass Values Item Ruler Small Washer 1 Small Washer 2 Small Washer 3 Large Washer 1 Large Washer 2 Loop of String 1 with Paper Clip at 0 cm Loop of String 2 with Paper Clip Number of Small Location of Mass [g] 11.56 g 1.85 g 1.85 g 1.85 g 24.30 g 24.30 g 1.20 g 1.22 g Washers at 0 cm Center of Mass of the Ruler, Xem [cm] Location of the 2 Large Washers for Balance, x [cm] Lever Arm of Small Washer(s) 20.5-0 [cm] Lever Arm for the Lever Arm of Large Ruler Mass Washer 20. 5 – Xem [cm] X-20.5 [cm] 1 washer for 1* Trial 15.2 cm 23 cm 20.5 cm 5.3 cm 2.5 cm 1 washer for 2nd Trial 15.2 cm 23 cm 20.5 cm 5.3 cm 2.5 cm 2 washers for 1 Trial 15.2 cm 23.6 cm 20.5 cm 5.3 cm 3.1 cm Number of Small Washers at 0 cm Data Table 2: Location of Masses for Balancing the Ruler Location of Center of Mass of the Ruler, xcm [cm] Location of the Large Washer for Balance, x [cm] Lever Arm of Small Washer(s) Lever Arm of Large Washer 2 washers for 15.2 cm 23.7 cm 20.5 cm 5.3 cm 3.2 cm 2nd Trial xcm - 0 [cm] x – Xcm [cm] 1 washer for 1" Trial 15.2 cm 16.5 cm 15.2 cm 1.3 cm 3 washers for 1" Trial 15.2 cm 24.5 cm 20.5 cm 5.3 cm 4 cm 1 washer for 2nd Trial 15.2 cm 16.6 cm 15.2 cm 1.4 cm 2 washers for 1 Trial 15.2 cm 17.7 cm 15.2 cm 2.5 cm 2 washers for 2nd Trial 15.2 cm 18 cm 15.2 cm 2.8 cm 3 washers for 2nd Trial 15.2 cm 24.4 cm 20.5 cm 5.3 cm 3.9 cm 3 washers for 1st Trial 15.2 cm 19.1 cm 15.2 cm 3.9 cm 3 washers for 2nd Trial 15.2 cm 19.1 cm 15.2 cm 3.9 cm Data Table 3: Torques Number of Small Washers at 0 cm Anti-clockwise Torque [cm g] {Show a sample Clockwise Torque [cm g] [Show a % Difference in Torques sample Calculation} 1 washer for 1" Trial Data Table 5: Torques Number of Small Washers at 0 cm a sample Calculation} 99.20 cm-g Anti-clockwise Torque [cm g] {Show Clockwise Torque [cm g] [Show a sample Calculation} % Difference in Torques 121.50 cm.g 20.2% Calculation} 1 washer for 1" Trial 28.12 cm-g 15.03 cm-g 60.66% 1 washer for 2nd Trial 99.20 cm-g 121.50 cm-g 20.2% 1 washer for 2nd Trial 28.12 cm-g 16.18 cm-g 53.91% 2 washers for 1" Trial 137.12 cm-g 150.66 cm-g 9.4 % 2 washers for 1" Trial 56.24 cm.g 28.9 cm-g 64.22% 2 washers for 2nd Trial 137.12 cm.g 155.52 cm-g 12.6 % 2 washers for 2nd Trial 56.24 cm.g 32.37 cm.g 53.87% 3 washers for 1" Trial 175.04 cm.g 194.40 cm-g 10.5% 3 washers for 1" Trial 84.36 cm.g 45.08 cm-g 60.96% 3 washers for 2nd Trial 175.04 cm.g 189.54 cm.g 8.0 % 3 washers for 2nd Trial 84.26 cm-g 45.08 cm.g 60.69% (Ctrl)

Stokes’ law describes sedimentation of particles in liquids and can be used to measure viscosity. Particles in liquids achieve terminal velocity quickly. One can measure the time it takes for a particle to fall a certain distance and then use Stokes’ law to calculate the viscosity of the liquid. Suppose a steel ball bearing (density 7.8103kg/m3 , diameter 3.0 mm) is dropped in a container of motor oil. It takes 12 s to fall a distance of 0.60 m. Calculate the viscosity of the oil.

A mountain 10.0 km from a person exerts a gravitational force on him equal to 2.00 of his weight. (a) Calculate the mass of the mountain. (b) Compare the mountain’s mass with that of Earth. (c) What is unreasonable or inconsistent? (Note that accurate gravitational measurements can easily detect the effect of nearby mountains and variations in local geology.)

A space station, in the form of a wheel 120 m in diameter, rotates to provide an artificial gravity of 3.00 m/s2 for persons who walk around on the inner wall of the outer rim. Find the rate of the wheels rotation in revolutions per minute that will produce this effect.

Review. A rifle bullet with a mass of 12.0 g traveling toward the right at 260 m/s strikes a large hag of sand and penetrates it to a depth of 23.0 cm. Determine the magnitude and direction of the friction force (assumed constant) that acts on the bullet.

Find the center of mass of a one-meter long rod, made of 50 cm of iron (density 8gcm3 ) and 50 cm of aluminum (density 2.7gcm3 ).

Unlike mass, weight is not a(n) ___ property. (1.4)

It has been suggested that rotating cylinders about 20 km in length and 8 km in diameter be placed in space and used as colonies. The purpose of the rotation is to simulate gravity for the inhabitants. Explain this concept for producing an effective imitation of gravity.

Check Your Understanding Consider the density required to make Earth a black hole compared to that required for the Sun. What conclusion can you draw from this comparison abut what would be required to create a black hole? Would you expect the Universe to have many black holes with small mass?

In a washing machine, water is extracted from clothes by a rapidly spinning drum ( Fig. 3.27). Explain the physics behind this process. Figure 3.37 Get the Water Out See Applying Your Knowledge Question 5.