i need help with these three questions please

Campus | Adelphi University x 5 Launch Meeting - Zoom X Homework #5 - Cold War Tech x A MTH 110 HW #5 - Chapter 3 Se x + C webassign.net/web/Student/Assignment-Responses/last?dep-27672355 Talking: Martin Farrell Radioactive Decay The radioactive element polonium decays according to the law given below where Q Is the Initial amount and the time t is measured in days. Q(t) = Q . 2 (t/140) If the amount of polonium left after 280 days is 55 mg, what was the initial amount present? mg Need Help? Read It 5. [-/3 Points] DETAILS TANAPMATH7 3.3.009. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER Radioactive Decay Phosphorus-32 (P-32) has a half-life of 14.2 days. If 200 g of this substance are present initially, find the amount Q(t) present after t days. (Round your growth constant to four decimal places. Q(t) = What amount (in grams) will be left after 11.1 days? (Round your answer to three decimal places.) How fast (in grams per day) is the P-32 decaying when t = 11.1? (Round your answer to three decimal places.) 9/day Need Help? Read It Watch It PRACTICE ANOTHER 6. [-/1 Points] TANAPMATH7 3.3.011. MY NOTES ASK YOUR TEACHER DETAILS Carbon-14 Dating Wood deposits recovered from an archaeological site contain 10% of the C-14 they originally contained. How long ago did the tree from which the wood was obtained die? (Assume the half life of carbon-14 is 5,730 years. Round your answer to the nearest whole number.) yr MacBook Air