Distinguish between current and current density.

1- the rate of flow of charge through a conductor is called current .whereas ,current density is the current per unit area of conductor

the only real purpose of sputnik 1 was to beat the us into space. we were getting close to launching a useful satellite, explorer 1 - which launched on january 31, 1958. the ussr had to beat that, so they launched sputnik 1 on october 4, 19