Using lens equation;
1/o + 1/i = 1/f; where o = Object distance, i = image distance (normally negative), f = focal length (normally negative)
Substituting;
1/o + 1/-30 = 1/-43 => 1/o = -1/43 + 1/30 = 0.01 => o = 1/0.01 = 99.23 cm
Therefore, the object should be place 99.23 cm from the lens.
Answer:
Answer is B.
Because the wavelength of infrared is shorter than microwave radiation
Answer: All apply
The periodic table is an arrangement of the chemical elements in the form of a table, ordered by:
-Their atomic number (number of protons)
-Their configuration of electrons
-Their chemical properties
It was progressively developed over time as the scientific knowledge advanced; for this reason many modifications and corrections might be done in the future.
Its usefulness lies in the fact that it allows the existing elements to be organized in a more structured and coherent way, according to the chemical properties they possess. Dividing the table into rows and columns, which represent the periods and groups or families.
Then, with the location and classification of an element according to its group, we can determine how it acts by knowing its chemical and physical characteristics.
This is how with this configuration can be distinguished 4 sets of chemical elements, according to the ease of their atoms to lose or gain electrons, transforming into ions: metals, semimetals, non-metals and noble gases.
This has helped to predict the existence of various elements that have not yet been discovered, because by elements already located in the table and the periodicity found, <u>there are still empty spaces that indicate the composition of the element that has not yet been found</u>.
In addition, this table helps to simplify in some way the teaching of chemical elements and facilitates their learning, as well as their usage in the development of technological innovations.
Answer:
<em>the phase relationship between two waves.</em>
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Explanation:
Coherence describes all properties of the correlation between physical quantities between waves. It is an ideal property of waves that determines their interference. In a situation in which there is a correlation or phase relationship between two waves. If the properties of one of the waves can be measure directly, then, some of the properties of the other wave can be calculated.
The solution for the problem is:
1 Watt = 1 Joule per second
1 Watt*second = 1 Joule
a Kilowatt is 1,000 Watts
an hour is 60 seconds times 60 minutes or 3,600 seconds
a Kilowatt * hour is 1,000 Watts in 3,600 seconds
15 W*h = 15,000 Watt*hour = 15,000 Watt * 3,600 seconds = 54,000,000
Watt*second
54,000,000 Watt*second = ? Joules
54,000,000 Joules / second = 54,000,000 Watts
