SOLUTION: PLEASE HELP ME TO SOLVE THE FOLLOWING PROBLEMS: 1) A ball is thrown downward from a window in a tall building. Its position at time t in seconds is s = -16t^2 + 32t, where s is in

Question 86959: PLEASE HELP ME TO SOLVE THE FOLLOWING PROBLEMS:
1) A ball is thrown downward from a window in a tall building. Its position at time t in seconds is s = -16t^2 + 32t, where s is in feet. How long (to the nearest tenth) will it take the ball to fall 81 feet?
2) Your company uses the quadratic model y = -11x^2 + 350x to represent how many units (y) of a new product will be sold (x) weeks after its release . How many units can you expect to sell in week 3?
3) The area of a square is numerically 3 less than the perimeter. Find the length of the side, if the side is greater than 1.
4) A ball is dropped from a cliff that is 352 feet high. The distance S (in feet) that it falls in t seconds is given by the formula S =16t^2. How many seconds (to tenths) will it take for the ball to hit the ground?
Answer by scianci(186) (Show Source):
You can put this solution on YOUR website!
1. Set your equation -16+32t = 81 and solve for t.
2. Plug in x = 3 into -11 + 350x
3. Make a table. Guess and check some side lengths greater than 1 and calculate the area and perimeter for each one and compare. When you find one whose area is 3 less than the perimeter, you have your answer.
4. Set 16 = 352 and solve for t.