Positive charge Q=5 nC is placed on a conducting spherical shell with inner radius R1=20 cm and outer radius R2=30 cm . A particle with charge q=4 nC is placed at the center of the cavity. What is the magnitude of the electric field at a point in the cavity, a distance r=12 cm from the center? (Take Coulomb's constant k=9x10 9 N m2 /C2)

For general projectile motion, when the projectile is at the highest point of its trajectory, its acceleration is zero? a)the horizontal and vertical components of its velocity are zero. b) its velocity is perpendicular to the acceleration. c)the horizontal component of its velocity is zero. d)its velocity and acceleration are both zero.

Apebble is thrown into a calm lake, ripples are formed from the center and move outward. the water particles in the lake travel in a circular pattern that moves up and down on the surface of a lake, and the energy travels a) diagonally. b) downward. c) horizontally. d) upward.

Which articulations allow for greatest range of motion?