In what do electromagnetic waves cause disturbances when they transfer
2 answers:
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Answer:
1280 mg
Explanation:
Radioactive decay is a phenomenon that occurs when a certain isotope of an element, said to be radioactive, decays, turning into a lighter nucleus and emitting radiation + energy in the process.
The radioactive decay of this isotope of polonium is described by the equation
where
is the amount of polonium left after time t
is the amount of polonium t time t = 0
is the half-life of the polonium, in days (it is the time it takes for the initial element to halve its amount)
IN this problem, we know that:
After t = 560 days, the amount of polonium left is . Therefore, we can re-arrange the equation, substituting t = 560 d, and solve for
to find the initial amount of polonium:
For a concave mirror, the radius of curvature is twice the focal length of the mirror:
where f, for a concave mirror, is taken to be positive.
Re-arranging the formula we get:
and since the radius of curvature of the mirror in the problem is 24 cm, the focal length is
where f, for a concave mirror, is taken to be positive.
Re-arranging the formula we get:
and since the radius of curvature of the mirror in the problem is 24 cm, the focal length is