Since it can be difficult to account for variations in speed over some interval, we sometimes pretend like an object traveled at a constant speed by playing a game of "What if?" After observing an object traveled some distance in some amount of elapsed time, we might ask ourselves, "What if the object DID travel at a constant speed? What would that speed have been?" Untried Roberta was walking away from her house. Seven seconds after leaving her house, Roberta was 26 feet from her front door. Nineteen seconds after leaving her house Roberta was 83.6 feet from her front door. image a. What was the change in time elapsed from the two moments described? Select an answer b. How far did Roberta travel during this time interval? Select an answer c. IF Roberta walked at a constant speed during this time interval, what would that constant speed have to be? Enter it below, then run the applet. If you are correct, then Roberta will be at the endpoint when the simulation ends. Select an answer NOTE: You must enter a final value in the box for the animation to run properly. It will not accept an expression that evaluates to the correct