Carbon 14 is used to determine the time an organism was living. The amount of carbon 14 an organism has is consistent with the atmosphere but when an organism dies carbon-14 decays at half-life of 5730 years. If an archaeologists measure the amount of carbon-14 in an organism and it was 25% of the total amount of atmospheric C-14, what is the age of the organism

At 20∘c, the hole in an aluminum ring is 2.800 cm in diameter. you need to slip this ring over a steel shaft that has a room-temperature diameter of 2.804 cm . 1. to what common temperature should the ring and the shaft be heated so that the ring will just fit onto the shaft? coefficients of linear thermal expansion of steel and aluminum are 12×10−6 k−1 and23×10−6 k−1 respectively.