Answer: B) (-x, y)
<u>Step-by-step explanation:</u>
If a coordinate is reflected across the y-axis, the y-coordinate stays the same but the x-coordinate changes signs.
Consider (1, 2) as the original point. Now reflect it across the y-axis. The new coordinate is (-1, 2). The y-coordinate stayed the same (2) but the x-coordinate changed signs (1 → -1).
The base area of this second rectangular prism is 51 cm²
The rectangular prism completely filled with sand has a base area of 85cm² and height of 15cm .
<h3>
</h3><h3>
volume of a rectangular prism</h3>
where
B = base area
h = height
Since the first rectangular prism was completely filled with sand and it completely filled the second rectangular prism, it means they both have the same volume.
Therefore,
volume of the first rectangular prism = volume of the second rectangular prism.
Therefore, the base area of the second rectangular prism can be calculated as follows:
volume = Bh
1275 = 25B
B = 1275 / 25
B = 51 cm²
learn more on prism here: brainly.com/question/2517494?referrer=searchResults
The mass of radioactive material remaining after 50 years would be 48.79 kilograms
<h3>How to determine the amount</h3>
It is important to note that half - life is the time it takes for the amount of a substance to reduce by half its original size.
Given the radioactive decay formula as
m(t)=120e−0.018t
Where
t= 50 years
m(t) is the remaining amount
Substitute the value of t
Find the exponential value
m(t) = 48.788399
m(t) = 48.79 kilograms to 2 decimal places
Thus, the mass of radioactive material remaining after 50 years would be 48.79 kilograms
Learn more about half-life here:
brainly.com/question/26148784
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Answer:
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Step-by-step explanation:
