HOMEWORK CHAPTER 5
1) A book on a table has a weight of 9.0 N. A force Ps = 3.0 N is required to start it sliding. But to keep it sliding at a constant speed, a minimum force Pk = 2.0 N is required. Find: a) the coefficient of static friction and b) the coefficient of kinetic friction. Ans. a. 0.33 b. 0.22 21) An object is moving on a curved path at a linear speed v = 30.0 m/s in a circle of radius r = 2.00 m. The object’s mass is m = 0.100 kg. Find the centripetal force. Ans. 45.0 N 29) The mass of the earth is, ME = 5.98 x 1024 kg, and the mass of the moon, MM = 7.36 x 1022 kg. The distance between their centers is 3.82 x 108 m. How far from the center of the earth is the center of mass of the Earth-Moon system? Ans. 4.64 x 106 m. [the radius is the earth is 6.37 x 106 m, placing the center of mass inside the earth.] SOLUTIONS (1) (a) The coefficient of static motion is described as the maximum ratio obtained between applied force and the normal force of a body in a s...