how much must lead has to be place on the top of the cube so that the top of the cube is level with water

The gravitational attraction between two objects will if one object acquires more mass .

Gam radio signals can usually be heard behind a hill, but fm often cannot. that is, am signals bend more than fm. explain. (radio signals, as we shall see, are carried by electromagnetic waves whose wavelength for am is typically 200 to 600 m and for fm about 3 m.)

What property is a characteristic of a substance that can be observed and does not change the identity of the substance