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

There is a theory that indicates that dinosaurs became extinct when about 65 million years ago, a large asteroid hit the earth surface. dust caused by this collision blocked the sunlight reaching the earth's surface and many forms of life became extinct due to the cold. fearing this threat, how large the radius of an asteroid should you be looking for if the dangerous asteroid size is approximately the same as the one that killed the dinosaurs? available data suggests that about 18% of that asteroid's mass ended up as a dust spread evenly over earth after eventually settling out of the upper atmosphere. about 0.0180 g/cm^2 of dust, which is chemically different than the earth's rock, covered the earth's surface. typical asteroids have a density of about 1.9 g/cm^3. now that we know the size of the asteroid, how much energy was released during impact, assuming all of it was just the kinetic energy of the asteroid right before the impact?

If a refrigerator is a heat pump that follows the first law of thermodynamics, how much heat was removed from food inside of the refrigerator if it released 380j of energy to the room?

The material that keeps its new shape after it is stretched is called?