A sample of plutonium-239 decays to one-eighth of its original amount after 7.236 x 104 years. What is its half-life?

What does it mean to transfer something

Consider a ball (with moment of inertia I=2/5MR^2) which bounces elastically off a surface. Assume that the ball's speed in the direction perpendicular to the surface is the same before and after a bounce.

Which of the following statements is/are true? A. Increasing the surface area over which a force is distributed increases the amount of stress acting on the surface. B.

How society has been benefited by the knowledge of physics

Can a twig float on water?

The gamma ray released by each decay carries 140kev of energy. find the total energy e released by decays in the 2 hours.

Think of the last five things you read. Now think of a type of reading you havent done recenty have never read. What kind of pattern do you see in your reading? What is your favorite type of reading and your least favorite type of reading?

Consider this statement: Air is matter. Which facts best support the statement? A. Balloons can be filled with air. B. Air is essential for life to exist. C. Air has mass. D. Air is not an element. E. To float on air is to be happy. F.

Hydroelectric power uses: wind water coal the sun

Two lightweight metal spheres are suspended near each other from insulating threads. One sphere has a net charge; the other sphere has no net charge. The spheres will: A. Attract each other B. Exert no electrostatic force on each other C.