SOLUTION: A worker dropped a screwdriver from the top of an elevator shaft. Exactly 5 seconds later he heard the sound of the screwdriver hitting the bottom of the shaft. How tall is the e

Algebra ->  Quadratic Equations and Parabolas -> SOLUTION: A worker dropped a screwdriver from the top of an elevator shaft. Exactly 5 seconds later he heard the sound of the screwdriver hitting the bottom of the shaft. How tall is the e      Log On


   

Question 320250: A worker dropped a screwdriver from the top of an elevator shaft. Exactly 5 seconds later he heard the sound of the screwdriver hitting the bottom of the shaft. How tall is the elevator shaft? Explain why the solution is 132.7 feet.
I know I am to use the following formula: s = .5gt^2+bt+c, where
s = height of object above ground
g = 32 on Earth - gravity on earth
t = the time since the start of the motion
b = the velocity of the object when t = 0, the initial velocity
c = the height of the object when t = 0, the initial height
I don't know how to figure out what b and c are so I solve my problem, any one out there who can help me?
Answer by scott8148(6628) About Me  (Show Source):
You can put this solution on YOUR website!
the screwdriver is dropped (not thrown) so ___ b = 0

"c" is the height of the shaft (what you are solving for)

s=0 when the screw driver hits the bottom at t=5

remember , "g" is negative (downward)

0 = .5(-32)(5^2) + (0)(5) + c



BIG HINT : the solution is NOT 132.7 ft