College Calculus - Vector fields, Work, and Circulation section. In the following exercises, find the work done by force field F on an object moving along the indicated path.

65. F (x, y) = - xi - 2yj

Where C is the unit circle centred at the origin with counterclockwise orientation. Note: If the initial point and ending point are the same we call this CIRCULATION.​

Ariana starts with 100 milligrams of a radioactive substance. the amount of the substance decreases by 20% each week for a number of weeks, w. the expression 100(1−0.2)w finds the amount of radioactive substance remaining after w weeks. which statement about this expression is true? a) it is the difference between the initial amount and the percent decrease. b) it is the difference between the initial amount and the decay factor after w weeks. c) it is the initial amount raised to the decay factor after w weeks. d) it is the product of the initial amount and the decay factor after w weeks.