200mg of uranium-238 has a half life of 4.5 billion years

How much will be left after 13.5 billion years

A: 200mg
B: 100mg
C: 50mg
D:25mg

One form of energy can be another type of energy. a. created to form b. transformed into c. destroyed and then created to form

Find the magnetic field a distance r from the center of a long wire that has radius a and carries a uniform current per unit area j in the positive z direction.

In the illustration, which two simple machines are being used to enable the student to reach the door? a. inclined plane and pulley b lever and wheel-and-axle c pulley and lever d wheel-and axle and inclined plane