Aforce acting on an object does no work if

How is the gravitational force related to the distance between two objects?

Individuals who live below the poverty line get seriously ill more often than those who do not what could be the hidden variable in this situation?

A10nc charge sits at a point in space where the magnitude of the electric field is 1500 n/c. what will the magnitude of the field be if the 10 nc charge is replaced by a 20 nc charge? assume the system is big enough to consider the charges as small test charges.