Problema Solution
If an object is propelled straight upward from ground level with an initial velocity of
80
80 feet per second, its height h in feet t seconds later is given by the equation
h equals negative 16 t squared plus 80 t
h=−16t2+80t. After how many seconds is the height
96
96 feet?
Answer provided by our tutors
We need to find t such that:
h(t) = 96
that is
−16t^2+80t = 96
........
click here to see the equation solved for t
........
t1 = 2 s
t2 = 3 s
This means the height of the object will be 95 feet to time, once, after 2 seconds - on the way up, and second time after 3 seconds - on the way down.