Carbon-14 (14 6C) dating is a method for finding the age of an organic artifact from the quantity of 14 6C it contains. Carbon-14, an unstable isotope of carbon, follows a well-known sequence of decay processes. The decay constants of these processes have been well established, allowing researchers to determine the age of an artifact knowing both the original amount of 14 6C and the current amount. In the lab, it is relatively easy to measure the activity of a sample and to estimate the mass of carbon in the sample. From these measurements, it is possible to find the age of the sample. An artifact is found in a desert cave. The anthropologists who found this artifact would like to know its age. They find that the present activity of the artifact is 15 decays/s and that the mass of carbon in the artifact is 0.100 kg. What is the age of the artifact? Be mindful of the units. Remember that the fraction of radioactive carbon isotopes in a naturally-occuring sample of carbon is about 1.3×10−12.
What is the age of the artifact in years?

Which term best describes the phrase “something that happens”?

American eels (anguilla rostrata) are freshwater fish with long, slender bodies that we can treat as uniform cylinders 1.0 m long and 10 cm in diameter. an eel compensates for its small jaw and teeth by holding onto prey with its mouth and then rapidly spinning its body around its long axis to tear off a piece of flesh. eels have been recorded to spin at up to 14 revolutions per second when feeding in this way. although this feeding method is costly in terms of energy, it allows the eel to feed on larger prey than it otherwise could. 1.a field researcher uses the slow-motion feature on her phones camera to shoot a video of an eel spinning at its maximum rate. the camera records at 120 frames per second. through what angle does the eel rotate from one frame to the next? 2. the eel is observed to spin at 14 spins per second clockwise, and 10 seconds later it is observed to spin at 8 spins per second counterclockwise. what is the magnitude of the eels average angular acceleration during this time? 3. the eel has a certain amount of rotational kinetic energy when spinning at 14 spins per second. if it swam in a straight line instead, about how fast would the eel have to swim to have the same amount of kinetic energy as when it is spinning? 4.a new species of eel is found to have the same mass but one-quarter the length and twice the diameter of the american eel. how does its moment of inertia for spinning around its long axis compare to that of the american eel?

The magnetic field inside a superconducting solenoid is 4.50 t. the solenoid has an inner diameter of 6.20 cm and a length of 26.0 cm. determine (a) the magnetic energy density in the field and (b) the energy stored in the magnetic field within the solenoid.