Earth rotates on an axis through its poles. The distance from the axis to a location on Earth 30º north latitude is about 3429.5 miles. Therefore, a location on Earth at 30º north latitude is spinning on a circle of radius 3429.5 miles. Compute the linear speed on the surface of Earth at 40º north latitude.

The weight of a radioactive isotope was 96 grams at the start of an experiment. after one hour, the weight of the isotope was half of its initial weight. after two hours, the weight of the isotope was half of its weight the previous hour. if this pattern continues, which of the following graphs represents the weight of the radioactive isotope over time? a. graph w b. graph x c. graph y d. graph z