Dielectric boundary conditions. At the interface between two dielectric materials with dielectric constants ε1 and ε2, the electric field intensity everywhere in material 1, � 1, has magnitude 1 and makes an angle α1 with the normal to the interface between the materials. There is a charge with surface charge density rhos sandwiched between the two materials. Determine the charge density rhos such that the electrical field intensity in material 2, �2 , is exactly equal to � 1.

Which describe reflection? check all that apply. light bounces off a boundary.

Adiver in midair has an angular velocity of 6.0 rad/s and a moment of inertia of 1.2 kg·m2. he then pulls is arms and legs into a tuck position and his angular velocity increases to 12 rad/s. the net external torque acting on the diver is zero. what is his moment of inertia in the tuck position?

Boxing gloves are padded to lessen the force of a blow. (a) calculate the force exerted by a boxing glove on an opponent’s face, if the glove and face compress 7.50 cm during a blow in which the 7.00-kg arm and glove are brought to rest from an initial speed of 10.0 m/s. (b) calculate the force exerted by an identical blow in the gory old days when no gloves were used and the knuckles and face would compress only 2.00 cm. (c) discuss the magnitude of the force with glove on. does it seem high enough to cause damage even though it is lower than the force with no glove?