Jim likes to rock climb in his spare time. Recently, he climbed down from the top of a cliff to the bottom. At the top, where Jim started, he was 2500 ft above the ground. He moved down the cliff at a speed of 20 ft/min. a) Write an equation to represent the height h, in feet, that Jim was above the ground after t minutes.
b) Make a table of values for Jim's height above the ground for values of t from 0 to 4.
c) What was Jim's height above the ground after 40 minutes?
d) How many minutes did it take to reach the ground?

Step-by-step explanation:

A) y = -20x + 2500

The above equation is written in slope intercept form - y=mx+b - the y int. is 2500, while the rate of change, aka the slope, is -20 feet per minute.

B) (0,2500)    (1,2480)    (2,2460)    (3,2440)    (4,2420)

For this question just plug in the x values 0 to 4 into the equation above. For example -20(0) +2500 = 2500

C) 1700 feet above the ground

Plug the number 40 into the equation above. -20(40) + 2500 = 1700

D) 125 minutes

The y-int. represents the time it takes him to reach the ground, this means you can set the equation equal to zero and solve to find the answer.

0 = -20x + 2500

subtract 2500 from both sides

-2500 = -20x

divide -20 from both sides

125 = x

b. 1.25 hr

step-by-step explanation:

if you have a constant speed of 60 mph, then you have a ratio between 60 mi. to 1 hr. dividing both sides by 60 we get the ratio

1 mi. to

then mult. both sides by 75 we get the ratio

75 mi. to

simplifying we get

75 mi. to

or 1.25 hr.