A woman standing on the ground watches an airplane fly by a mountain on a clear summer day. Her reference point for the moving plane would be: a. There is no reference point
b. The ground
c. The mountain
d. A person in the plane

The electric potential v is constant everywhere within a certain region of space. which statement below is true? the choices are: the electric field is also constant (but not zero) within the region. a charged particle placed within the region will experience an electric force. the electric field is zero everywhere within the region. the electric field varies from place to place within the region.