Mr. Richard's science class is conducting a variety of experiments with projectiles and falling objects. Two groups of students are using a slingshot to launch tennis balls from ground level, and two groups are dropping tennis balls from the fire escape. Below are descriptions of the parameters with which each group launches or drops their tennis balls.

Group A launches a tennis ball straight up with an initial velocity of 19 meters per second.
Group B launches a tennis ball straight up with an initial velocity of 50 feet per second.
Group C drops a tennis ball from a height of 19 meters.
Group D drops a tennis ball from a height of 50 feet.
Determine which group's activities can be modeled by the following equations, where h is the current altitude of the tennis ball.

The biologist has a second culture to examine. she knows that the population of the culture doubles every 15 minutes. after 1 hour and 15 minutes, her assistant found that 80,000 bacteria were present. a) what was the size of the initial population? b) predict the size of the culture at t=3 hours. what was the size of the population at 40 minutes? explain and justify your answers. c) create a graph of the population as a function of time. find an equation that can be used to predict the size of the population at any time t. d) examine the rate at which the bacteria culture is growing. how fast is the culture growing after 1 hour? after 1.5 hours? after 2 hours? use a time interval of h = 0.01 hours to estimate these rates. interpret these rates in terms of the context of the problem situation. how do these three rates compare?