Question

The height, H, in feet, of an object dropped from the top of a building after t seconds is given by H(t) = -16t² + 144. How many feet did the object fall between one and two seconds after it was dropped? Determine algebraically how many seconds it will take for the object to reach the ground.​

Answer 1

Explanation:

if t = 1

H = -16 + 144

H = 128 ft

if t = 2

H = -16(2)² + 144

H = -16 (4) + 144

H = -64 + 144

H = 80 ft

128 - 80 = 48 ft

ground = height equals to 0

-16t² + 144 = 0

-16/8 t² + 144/8 = 0

-2t² + 18 = 0

-2/2 t² + 18/2 = 0

-t² + 9 = 0

t² -9 = 0

t² = 9

t = √9

t = 3 seconds