The linear model represents the height, f(x), of a water balloon thrown off the roof of a building over time, x, measured in seconds:

a linear model with ordered pairs at 0, 60 and 2, 80 and 3, 80 and 4, 20 and 6, 0 and 7, 0 and 8, 0. the x axis is labeled time in seconds, and the y axis is labeled height in feet.

part a: during what interval(s) of the domain is the water balloon's height increasing? (2 points)

part b: during what interval(s) of the domain is the water balloon's height staying the same? (2 points)

part c: during what interval(s) of the domain is the water balloon's height decreasing the fastest? use complete sentences to support your answer. (3 points)

part d: use the constraints of the real-world situation to predict the height of the water balloon at 10 seconds. use complete sentences to support your answer. (3 points)