Question

When thrown upward at a velocity of 16 feet per second, the height f of

an object in feet at the end of t seconds is given by the formula f =-16t+16t?
After approximately how many seconds will an object reach a height of 32 feet?
5 seconds
2 seconds
3 seconds
None of the choices are correct.

Answer 1

b) 2 seconds

t=2 seconds will an object reach a height of 32 feet

Explanation:

Explanation:-

Given height f =-16t+16t² ...(i)

Differentiating equation (i) with respective to 't'

`(df)/(dt) = -16(t) +16(2t)`

Equating Zero

- 32 t + 16(2t) =0

- 16 t = -32

t = 2 seconds

Given height f =-16t+16t²

f = - 16 (2) +16(4) = -32 +64= 32feet

Conclusion:-

t=2 seconds will an object reach a height of 32 feet