Please help!! I need to turn it in soon! :) You find a fossil and want to determine its age using radiometric dating. You know
that Element X decays into calcium with a half-life of 1600 years. If you determine
that the fossil contains 3000 particles of element X, and 3000 particles of calcium,
how old is the fossil? Briefly explain your thinking.

Aspacecraft can attain a stable orbit 300 kilometers above earth if it reaches a velocity of 7.7 kilometers per second. the formula for a rocket's maximum velocity v in kilometers per second is vequalsminus0.0098tplusc ln upper r, where t is the firing time in seconds, c is the velocity of the exhaust in kilometers per second, and r is the ratio of the mass of the rocket filled with fuel to the mass of the rocket without fuel. find the velocity of a spacecraft whose booster rocket has a mass ratio of 20, an exhaust velocity of 2.1 km/s, and a firing time of 15 s. can the spacecraft achieve a stable orbit 300 km above earth?