Answer:
shadow length 7.67 cm
Explanation:
given data:
refractive index of water is 1.33
by snell's law we have


solving for



from shadow- stick traingle


s = 19tan22 = 7.67 cm
s = shadow length
The relationship between the frequency (f) of an electromagnetic wave, the speed of the wave (which is the speed of light, c) and its wavelength

is given by

Since the wavelength of the radiation in the problem is

, by substituting numbers in the formula we can get the frequency:
This question may require more information for an accurate answer. If the clouds are observed west of the city and they are moving in a westerly direction it means that the clouds are moving away. Precipitation refers to rainfall, sleet, hail or snow. Since no reference was made to the temperature, season or location of the city it could be rain or snow clouds. The clouds are moving away from the city so the possible answers could be b. or d. Furthermore, by dividing the distance by the speed one would get an answer of twenty four hours. So even if the clouds were moving towards the city it would take a day to reach and precipitation would not be likely in 24 hrs.
Answer: A positively charged ion/ cation
Explanation: When an atom loses all of its electrons, it becomes a positively charged ion. Also referred to as the cation, the object will have a shortage of electrons, leading to a positive charge. Keep in mind that an atom will become positive if it loses electrons, and will become negative if it gains electrons.
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