Four electrons are located at the corners of a square 10.0 nm on a side, with an alpha particle at its midpoint. How much work is done by the Coulomb force when the alpha particle moves to the midpoint of one of the sides of the square?
Express your answer in joules.

Amachinist needs to remove a tight fitting pin of material a from a hole in a block made of material b. the machinist heats both the pin and the block to the same high temperature and removes the pin easily. what statement relates the coefficient of thermal expansion of material a to that of material b? a) the situation is not possible, heating block b will shrink the hole in the material as the material expands with increasing temperatureb) material b has the same coefficient of expansion as does material ac) material b has a negative coefficient of expansion and a has a positive coefficient of expansiond) material a has a greater coefficient of expansion than does material be) material b has a greate

Galileo was the first to notice that the moon has craters, valleys, and mountains. how might this have changed people's perception of the moon at the time?

All the simple machines make work easier to do by changing the or of a force. a. size; type b. work; type c. size; direction d. type; direction