Math Homework Help (ASAP DUE TODAY)!!!!!! URGENT

Question

At the surface of the ocean, the water pressure on the submarine is the same as the air pressure above the water-about 15lb/in^2.Below the surface, the water pressure increases by about 9lb/in^2 for every 20 ft of descent. Part A Write an equation in slope-intercept form showing the pressure p, in pounds per square inch, on the submarine at different depths d, in feet.Then graph the equation. Part B On another dive, the submarine descends at a steady rate from sea level.After 20 s the pressure guage reads 100 lb/in^2.What is the rate of descent for the submarine?Show the steps of your solution.If necessary, round your answer to the nearest tenth. I really need help and have it due today.Please help

Answer 1

At depth level d=zer0, Pressure P = 15

(0,15)

slope m = 9/20 <---- the pressure increases 9 lbs/in^2 every

20 feet of descent

(a) P = (9/20)*d + 15

You can graph this line at www.desmos.com

Note that at 20 feet deep, the pressure is 24 lbs/in^2

(b) at time zero (t=0), the pressure is P=15 lbs/in^2

at time t=20 sec, the pressure is P=100 lbs/in^2

the slope is (100-15)/20 = 85/20 = 17/4 = 4 and 1/4 = 4.25

P = 4.25t + 15