1) Na figura 1 está representada a configuração de uma onda mecânica que se propaga com velocidade de 20 cm. A frequência da onda, em hertz, vale: * 1 ponto Figura 1 Figura 1 a) 5,0 b) 101) Na figura 1 está representada a configuração de uma onda mecânica que se propaga com velocidade de 20 cm. A frequência da onda, em hertz, vale: * 1 ponto Figura 1 Figura 1 a) 5,0 b) 10 c) 20 d) 25 c) 20 d) 25

Zoe is investigating the composition of substance a, an unknown substance. using chemical processes, she analyzes substance a and determines it is composed of sodium, oxygen, and hydrogen atoms in a ratio of 1 : 1 : 1. what is substance a? a. a compound b. an element c. a heterogeneous mixture d. a homogeneous mixture

Americium-241 undergoes fission to produce three neutrons per fission event. if a neutron-absorbing material is mixed in with this sample so that the rate of neutron production drops down to 1.8 neutrons per fission event, which will be effective at achieving a critical mass? check all that apply. remove a deflective shield surrounding the sample. remove absorbent material mixed in with the sample. compress the sample of americium-241.

Pastoral farming is best described as a. a method of raising livestock and moving herds b. an african method of agriculture c. a method of cultivating crops on poor soils d. a common method of desert farming select the best answer from the choices provided a b c d