When running a 100-meter race Usain Bolt reached his top speed when he was 55 meters from the starting line and had been running for 4.6 seconds since the start of the race. He passed the 80 meter line of the race when he had been running for 7.8 seconds since the start of the race. Let
t
represent the number of seconds since the start of the race.

Let
d
represent Usain's distance from the starting line of the race.

Anew obstacle course is home to several new types of challenging obstacles. one such obstacle is traversing a 15-stair staircase. to make it more challenging, the stairs are not uniformly spaced. rather, the vertical space between consecutive stairs for the first 10 stairs is 113 feet and the vertical space for the last 5 stairs is 134 feet. what is the total vertical distance traveled ascending and descending the entire 15-stair staircase?