[MOVED] find area, given dimensions / find time of fall /

[Nikki1984]

I need help on 3 problems, i have the answers for 2 but I don't know how to get them. Any help would be much appreciated.

1. The length of Mary Adam's Rectangular flower garden is 6 feet more than its width. A walkway 3 feet wide surrounds the outside of the garden. The total area of the walkway itself is 288 square feet. Find the dimensions of the garden.
ANSWER: 18ft by 24ft but I don't know how to get that answer ...

2. The distance, d(t), fallen by a freefalling body can be represented bu the formula d(t)=vt-1/2gt^2? Where v is the initial velocit and g represents the acceleration due to gravity. The acceleration due to gravity is 9.8 m/s^2. If a rock is thrown downward with an initial velocity of 4m/s from the edge of the North Rim of the Grand Canyon, which is 1750 meters deep, determine how long it will take the rock to reach the bottom of the Grand Canyon?
ANSWER: ? (i know this is like a physics question but it is for my precalc class ...)

3. When an object is projected upward its height in feet above the ground, d(t), is given as a function of time, t in seconds, by the formula d(t)=vt-1/2gt^2. The acceleration due to gavity is g is 32 ft/s^2. If Jason Kendall of the Pittsburgh Pirates hits a ball straight upward with an initial velocity, v, of 80 ft/s determine the time that the ball is in the air.
ANSWER: 5 seconds (this one totally confuses me ..)

Thanks for any help.

 

[stapel]

1) Draw the picture of the garden. Pick a variable for the width. Write an expression, in terms of this variable, for the length. Label the picture accordingly.

Draw the walkway around the garden. Label the width on all four sides as "3". Divide the walkway drawing into squares and rectangles, associated with the garden. Figure out expressions, in terms of the "width" variable and the "length" expression, for the areas of the long bits of the walkway. (The corners, of course, are 3×3 = 9 square feet.)

Sum the areas. Set equal to the given total. Solve for the variable. Back-solve for the garden's dimensions.

2) You are given the formula for the height, with d(0) = 0, so you're using the starting height as the origin. You are given that g = 9.8 and v = -4. Plug them into the given formula.

You are asked to find the time t when the height is -1750. So plug "-1750" in for the distance, and solve for the time "t".

3) You are given the height formula. You are also given that g = 32 and v = 80. You are asked to find when the ball is on the ground. What is the height when the ball is on the ground? Plug this value in for the height, and solve for "t".

If you get stuck, please reply showing what you have tried and how far you have gotten. Thank you.

Eliz.