hint: v= 80, s=0, h=96; divide all terms by 16.

Question

An object is thrown upward from the ground with a speed of 80 feet/second. Find the times at which the object will be 96 feet high.

Answer 1

h = -32*(1/2)*t^2 +vt +s

note:  the 32 is because 32 ft /  sec^2 is the acceleration due to gravity on Earth.

note:  the acceleration is negative because gravity is pulling the object back down

note:  the (1/2)*t^2 is because of something called integrals and derivatives, which you'll learn about in calculus

96 = -16t^2 + 80t +0

16t^2 -80t +96 = 0

all three numbers are divisible by 16 so

t^2 -5t +6 = 0

(t-3)(t-2) = 0

t = 2 and 3

Answer:  t = 2 seconds (on the way up) and t = 3 seconds (on the way down)

Comments

Thank you so much it really helped !