What would happen if we used up all the coal on earth?
a. we would make more in a coal factory.
b. more coal would quickly form underneath the earth's surface
c. it would take millions of years to replace. (it would not be able to be replaced in time for us to continue to use.)

Carbon 14 is a naturally occurring stable

Asolid round steel rod 6.25 mm in diameter and 375 mm long is rigidly bonded to the end of solid square brass rod 25 mm on a side and 300 mm long. the geometric axes of the bare are along the same line. an axial tensile force of 5.4 kn is applied at the extreme ends of the assembly. for steel e = 200 gpa and for brass e = 90 gpa. determine the total elongation for the assembly.

You charge a parallel-plate capacitor, remove it from the battery, and prevent the wires connected to the plates from touching each other. when you increase the plate separation, what happens to the following quantities?