The half-life of iodine-131 is 8.07 days. If 0.25 g are left after 45.7 days, how many grams were in the original sample?

The desk has a weight of 75 lb and a center of gravity at g. determine the initial acceleration of a desk when the man applies enough force f to overcome the static friction at a and b. also, find the vertical reactions on each of the two legs at a and at b. the coefficients of static and kinetic friction at a and b are ms = 0.5 and mk = 0.2, respectively

Which situation will have the highest resistance? a.long wire and high temperatureb.short wire and high temperaturec.long wire and cold temperaturedshort wire and low temperature

Apulley with mass mp and a radius rp is attached to the ceiling, in a gravity field of 9.81 m/s2 and rotates with no friction about its pivot.