An object is placed 5 cm in front of a plane mirror, how
far behind the mirror is the image of the object?

A.) 2.5
B.) 10
C.) 7.5
D.)
5

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