The uniform bar of mass m and length l is balanced in the vertical position when the horizontal force p is applied to the roller at a. determine the bar's initial angular acceleration and the acceleration of its top point b.

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.)

This city is the capital of the state of georgia since 1868 and was burned during the civil war.

Patients with brain tumors may elect to have a procedure known as gamma knife. in a typical gamma knife procedure gamma rays are directed toward a tumor with contact to surrounding tissues. limiting contact between gamma rays and healthy tissue is important because