Question 1187719
The altitude, A, of an airplane follows a linear model given by:
A = mt + b
Where t is the time in seconds after taking off. 
-----
5 seconds after taking off from the ground, the plane is 1200ft above sea level and 60 seconds after take-off, the plane is 3400ft above sea level.
1200 = 5m + b
3400 = 60m + b
------------------------ Subtract
-2200 = -55m
m = 40 ft/sec
-----------------------
a) Solve for m and b
Sub for m and find b
------------
b) How high is the ground above sea level?
That's b.
We don't need hints.
=============================
 (Hint: the plane is on the ground just before take-off)
===================================
c) Find rate of altitude increase over period 0 < t < 775? Both less than should be less than or eq
That's m.