SOLUTION: a rock falls from a tower that is 176ft high. as it is falling , its height is given by the formula h=176-16t^2. how many seconds will take for the rocks to hit the ground (h=0)?

Algebra.Com
Question 77320: a rock falls from a tower that is 176ft high. as it is falling , its height is given by the formula h=176-16t^2. how many seconds will take for the rocks to hit the ground (h=0)?
Answer by jim_thompson5910(35256)   (Show Source): You can put this solution on YOUR website!
If we let h=0 then we get

Now rearrange the quadratic in descending order

Now use the quadratic formula to solve for t:
Solved by pluggable solver: SOLVE quadratic equation with variable
Quadratic equation (in our case ) has the following solutons:



For these solutions to exist, the discriminant should not be a negative number.

First, we need to compute the discriminant : .

Discriminant d=11264 is greater than zero. That means that there are two solutions: .




Quadratic expression can be factored:

Again, the answer is: -3.3166247903554, 3.3166247903554. Here's your graph:



We must disregard the negative answer (a negative time doesn't make any sense), so our answer is
t=3.3166
So it takes about 3.3 seconds for the rock to hit the ground

RELATED QUESTIONS

a rock falls from a tower that is 176ft high. As it is falling its height is given by the (answered by jim_thompson5910,rajagopalan)
A rock falls from a tower that is 132.3 m high. As it is falling, its height is given by... (answered by Alan3354)
A rock falls from a tower that is 304 feet high. As it is falling, its height is given... (answered by stanbon,mananth,Alan3354)
Round to the nearest tenth, if necessary. A rock falls from a tower that is 432 feet... (answered by vleith)
Round to the nearest tenth, if necessary. A rock falls from a tower that is 432 feet... (answered by stanbon)
A rock falls from a tower that is 480 feet high. As it is falling, its height is given by (answered by ewatrrr)
A rock falls from a tower that is 208 feet high. As it is falling, its height is given by (answered by nerdybill)
A rock falls from a tower that is 400 ft high. AS it is falling, its height is given by... (answered by mananth)
A rock falls from a tower that is 192 feet high. As it is falling,its height is given by... (answered by checkley77)