Radioactive iodine (radioiodine) is given to patients with some forms of thyroid cancer in order to destroy the cancer cells. 1311 has a half-life of 8 days. Women who have been treated with 1311 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 1311 will still be in her system when she can
safely become pregnant?

f=ma newton

f=100x2.5=250n

i think it would be 5

initial speed when it is dropped is 150 ft/s

now at the same moment the acceleration due to gravity is perpendicular to its velocity

so as we know that

now we have centripetal acceleration a = 32 ft/s^2 as its perpendicular to velocity

while tangential acceleration at the same moment will be zero

so

now radius of curvature is given as

so the radius of curvature just after it is dropped is 703.125 ft

distance = 150m

displ = root (50 ^2 + 100^2)

root(2500+10000)

root 125000