Question
The table shows the height of an elevator above ground level after a certain amount of time. Let y stand for the height of the elevator in feet and let x stand for the time in seconds. Which equation models the data below?
Time (s) Height (ft)
10 235
20 220
40 190
60 160
Time (s) Height (ft)
10 235
20 220
40 190
60 160
Answers
Reiny
let's assume the relationship is linear
slope between first pair of points = (220-235)/(20-10) = -15/10 = -1.5
so y = -1.5t + b
using (10,235)
235 = -1.5(10) + b
235 = -15 + b
b = 250
y = -1.5t + 250
testing for last data value
when t=60
y = -1.5(60) + 250 = 160 , yeah!
slope between first pair of points = (220-235)/(20-10) = -15/10 = -1.5
so y = -1.5t + b
using (10,235)
235 = -1.5(10) + b
235 = -15 + b
b = 250
y = -1.5t + 250
testing for last data value
when t=60
y = -1.5(60) + 250 = 160 , yeah!