A teacher swings a pendulum towards her chin as it swings back it does NOT hit her why is that?

i think the answer would be b

in this image, you can see solar radiation going through ocean water.

no image, but probably absorption

frequency or wavelenth of em radiation in a vacuum

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