Fireworks by ewghwehws


Fireworks were launched with an upward
velocity of 64 ft/sec from a platform 80
feet above the ground. The height h(t) of
the cardboard shell containing the fireworks
is given by :
     ht   16t 2  64t 80
What is the height of the shell                64 ft/sec
2 seconds after launch?
How many seconds elapse before                             feet

the (spent) shell drops back to
the ground?
Picture Frame
A picture frame measures 14 inches
by 20 inches along the outside and has
160 in2 of picture showing.
                                     14 inches
How wide is the frame?

                                                 160 in2

                     20 inches
From geometry there is only one right triangle whose sides
can be given by 3 consecutive integers. What are they?
Antenna Height
A 20 foot long guide wire is stretched
from the top of an antenna tower
to the ground. The height of the
antenna tower is 4 feet more than the
distance from the base of the tower
to the ground end of the wire.
What is the height of the tower?         20 feet
Cost and Revenue
The cost of making x doohickeys is given by the function
               1 2
        Cx   x  2x 1
The revenue function for doohickeys is
              5 2
        Rx  x  2x

What is the cost of making 20 doohickeys?
What is the revenue from selling 20 doohickeys?
At what production level does cost equal revenue (this is
known as the break-even point)?
    The “Famous” Box Problem
    A rectangular piece of cardboard is twice as long as it is wide.
    Squares 2 inches on a side are cut out of each corner and the
    resulting flaps are turned up to make a box whose volume is
    480 in3. What are the original dimensions of the piece of
    cardboard ?

                                            480 in3


                           2 in.

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