The half-life of plutonium-238 is 87.7 years. What percentage of the atoms in a sample of plutonium-238 will remain radioactive after 263.1 years?

%

What percentage of the atoms in the same sample of plutonium-238 will have changed to a stable isotope after 263.1 years?

%

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

The ratio of lift to drag l/d for a wing or airfoil is an important aerodynamic parameter, indeed, it is a direct measure of the aerodynamic efficiency of the wing. if a wing is pitched through a range of angle of attack, l/d first increases, then goes through a maximum, and then decreases. consider an infinite wing with an naca 2412 airfoil. estimate the maximum value of l/d. assume that the reynolds number is 9x10^6.

In a heat engine if 1000 j of heat enters the system the piston does 500 j of work, what is the final internal energy of the system if the initial energy was 2000 j? 1. write the equation 2.list out your known variables 3.plug the numbers into the equations 4.solve 5.write your solution statement that includes initial energy and final