Space awareness is a concept that needs to be taught at the beginning of a physical education program because

Which of the following is another term for a planned economy

Acar of mass 800kg is moving at a speed of 2.2m/s.

The radioactive isotope of lead, pb-209, decays at a rate proportional to the amount present at time t and has a half-life of 3.3 hours. if 1 gram of this isotope is present initially, how long will it take for 80% of the lead to decay? (round your answer to two decimal places.)