Answer:
Step-by-step explanation:
Determine which climbed at a constant rate
A constant rate would produce a straight line. The slope is the same for all the data for that climber. We can either calculate the slope between the first and last intervals and see if the slope changes. Or we can graph the points, which I chose to do. See the attachment.
Note that Joe's rate is not constant. It appears as though he's wearing down. Both Zas and Stephon have constant slopes, so their climbing rates are constant over the period measured.
The slope is the climbing rate:
Joe: Not Constant
Zas: 2.5 feet/sec
Stephon: 4.0 feet/sec
Time to Reach 30 feet
Joe: Unknown - he's slowing down at an unpredictable rate.
For Zas and Stephen, use their slopes in the expression:
Use m for slope (ft/sec): y = m(t) where t is time in seconds
Zas: 2.5 feet/sec: y = 2.5(t) Time to reach 30 is 30/2.5 or 12 sec.
Stephon: 4.0 feet/sec: y = 4.0(t) Time to reach 30 is 30/4.0 or 7.5 sec.
