Athin disk with a circular hole at its center, called an annulus, has inner radius r1 and outer radius r2. the disk has a uniform positive surface charge density σ on its surface.

An ice-making machine inside a refrigerator operates in a carnot cycle. it takes heat from liquid water at 0.0 degrees celsius and rejects heat to a room at a temperature of 19.2 degrees celsius. suppose that liquid water with a mass of 76.3kg at 0.0 degrees celsius is converted to ice at the same temperature. take the heat of fusion for water to be l_f = 3.34*10^5 j/kg.how much energy e must be supplied to the device? express your answer in joules.

Amagnetic field applies forces on: a)static chargesb)moving chargesc)water flow

The reason a penny thrown straight up inside a bus will come back to your hand is that you,the bus,the air inside the bus, and the penny are all moving at the same velocity. true or false