For what reason did the early Greeks believe the appropriate shape for an orbit was round? Select all that apply. Ptolemy proved that orbits were circular.
Greeks believed the circle represented perfection.
The circular orbit and epicycles allowed for relatively accurate predictions in the placement of the planets.
The earth was known to be round at this time.

Um vetor representa um deslocamento cujo módulo é 20 m. se v faz um ângulo de 60 graus com a horizontal, qual é o valor das componentes horizontal e vertical deste vetor?

Eddy whose mass is 55kg climbs up the 1.50 meter high stairs in 2s.calculate eddy’s power rating

Starting with only the balmer series light (visible light), how could we ensure that the solar panels generate a current that mark can use for his power station? a)by gradually increasing the brightness (amount) of light that we shine on it. b)by gradually increasing the frequency of the light we shine on it. c)by gradually increasing the wavelength of the light that we shine on it.