Un atleta corre por un pista circular de 100 metros de radio a una velocidad de 7 m/seg. Un amigo lo está mirando desde un punto a 200 metros del centro de la pista.
¿Qué tan rápido cambia la distancia entre el amigo y el atleta cuando la distancia entre
ellos es de 200 metros?

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.