A uniform spherical shell of mass M = 4.5 kg and radius R = 8.5 cm can rotate about a vertical axis on frictionless bearings, see Fig. 1. A massless cord passes around the equator of the shell, over a pulley of rotational inertia I = 3 × 10−3 kgm2 and radius r = 5 cm, and is attached to a small object of mass m = 0.6 kg. There is no friction on the pulley’s axle; the cord does not slip on the pulley.
1. What is the acceleration of the system?
2. What is the speed of the object when it has fallen 82 cm after being released from rest.

Moon effect. some people believe that the moon controls their activities. if the moon moves from being directly on the opposite side of earth from you to being directly overhead, by what percentage does (a) the moon's gravitational pull on you increase and (b) your weight (as measured on a scale) decrease? assume that the earth–moon (center-to-center) distance is 3.82 × 10^8 m, earth's radius is 6.37 × 10^6 m, moon's mass is 7.36 × 10^22 kg, and earth's mass is 5.98 × 10^24 kg.

What should the power status of a circuit be when measuring resistance with an ohmmeter?

1. what is the relationship between wavelength and the penetrating power of an electromagnetic wave? a) the penetrating power has no relationship to the wavelength. b) the penetrating power increases as the wavelength increases. c) the penetrating power decreases as the wavelength increases. d) the penetrating power decreases as the wavelength decreases. 2. as ice melts and turns into water, the speed of sound through the material would most likely do what? justify your answer. a) the speed would not change because the material is always water. b) the speed of sound would increase because the density of water is less than that of ice. c) the speed of sound would increase because energy is added to ice in order to make it melt. d) the speed of sound would decrease because sound travels faster through solids than liquids. 3.which of these waves need a medium to travel through? a) sound b) x-rays c) infrared rays d) visible light