The LD50 for caffeine is 192mg/kg. How many cups of caffeine would provide a lethal dose for a 150lb person? (1cup contains 92mg of caffeine and 2.21 lb=1kg)

What is the area in square meters of 448 g ai foil that has a thickness of 23921 nm? the density is 2.70 g/cm

A40 kilogram skier starts at the top of a 12 meter high slope. at the bottom, she is travelling 10 meters per second. how much energy does she lose to friction

At a certain temperature the rate of this reaction is first order in hi with a rate constant of : 0.0632s2hig=h2g+i2g suppose a vessel contains hi at a concentration of 1.28m . calculate how long it takes for the concentration of hi to decrease to 17.0% of its initial value. you may assume no other reaction is important. round your answer to 2 significant digits.