Um tubo sonoro, aberto nas duas extremidades, tem comprimento de 40 cm. Em certo instante o ar dentro do cubo está vibrando em seu 4° harmônico. sendo 340 m/s a velocidade do som no ar, qual é a frequência do som emitido pelo tubo?

a)425 Ghz

b)850 Hz

c)1,275 kHz

d)1,7 kHz

e)2125 Hz

Which type of wave can travel without a medium

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.

The sun’s mass is 2.0×10^ 30 kg, its radius is 7.0×10 5 km, and it has a rotational period of approximately 28 days. if the sun should collapse into a white dwarf of radius 3.5×10 3 km, what would its period be if no mass were ejected and a sphere of uniform density can model the sun both before and after?