Radioactive iodine (radioiodine) is given to patients with some forms of thyroid cancer in order to destroy the cancer cells. 131I has a half-life of 8 days. Women who have been treated with 131I are advised to not become pregnant for 180 days (approximately 6 months) to avoid the radioactive contamination of a developing fetus. If a woman has been given a dose of 10 mCi (millicurie, a measurement of radiation), how much 131I will still be in her system when she can safely become pregnant?

A. 1.7 x 10-6 mCi
B. 22.5 x 10-6 mCi
C. There will be no iodine-131 left in her system after 180 days.
D. 3.125% of the original isotope

Fft review: linspace, fs, fftshift, nfft 1. generate one second of a cosine of w,-10hz sampled at f, = 100hz and assign it to x. define a tt as your time axis 2. take 64 points fft. 3. as you remember, the dft (which the fft implements) computes n samples of s2t where k-0,1,2, n -1. plot the magnitude of this 64-points fft at range 0 to 63, what do you think of this graph? 4â·to get the x-axis into a hz-frequency form, plot this 64-points fft between-50 to 50 (the 100hz sampling rate) and have n-points between them. 5. according to your figure, what frequency is this cosine wave at? 6. remember that the fft is evaluating from 0 to 2ď€. we are used to viewing graphs from-ď€ to ď€. therefore, you need to shift your graph. 7. now according to your shifted graph. what frequency is this at? 8. note that the spikes have long drop-offs? try a 1024-point dft. note that the peak is closer to 10 and the drop-off is quicker. although, now sidelobes are an issue

An object weighs 40n in air, weighs 20n when submerged in water and 30n when submerged in a liquid of unknown density. what is the density of the liquid?

The radius of a sphere is increasing at a rate of 9 cm/ sec. find the radius of the sphere when the volume and the radius of the sphere are increasing at the same numerical rate.