A stone is launched into the air from a height of 384 feet. The height, h , of the stone, in feet, t seconds after launch is given by the formula h=-16t2+32t+384 . After how long will the stone hit the ground? 12 seconds 6 seconds -4 seconds 4 seconds

The correct option is b: 6 seconds.      

Step-by-step explanation:

The formula is:

Where:

t: is the time

h: is the height = 384 ft

When the stone hit the ground, h = 0

To solve the above quadratic equation we need to use the following formula:

  (1)

Where:    

a: is the coefficient of t² = -16

b: is the coefficient of t = 32    

c: is the independent term = 384

By entering the above values into equation (1) we have:

Since we can not take the negative value of time (t₂) equal to -4, the answer is 6 seconds.  

Therefore, the stone will hit the ground in 6 seconds. The correct option is b: 6 seconds.      

I hope it helps you!  

7! = 7×6×5×4×3×2

3! = 3× 2

as 7! is multiple of 3! because 7! contains 3! that is 3× 2 as factor

so 7! /(3! ) = 7× 6× 5× 4

= 42 × 20

= 840

its b) 840✌✌✌

dhruv⭐

this answer is !