posted by jennifer on .
I have 12 word problems to do for my class today.
I am not very good at them.
Any suggestions on how to set them up?
they vary from question to question
Turn the word problems into equations, and solve for the unknown quantity or quantities.
Why not give us one or two examples to show you the process?
A model rocket is launched vertically upward from the top of a cliff 144 feet above sea level. This translates to the model y = -16t^2 + 128t + 144 where y is the height in feet and t is the time in seconds after it was launched. After it is launched, when will the rocket hit the water?
It will hit the water when y = 0. You have to solve the quadratic equation.
You can rewrite it (by dividing both sides by -16)
t^2 - 8t - 9 = 0
which factors to
(t-9)(t+1) = 0
Therefore t = 9 seconds is when it hits the ground. The other solution t = -1 second has no meaning
A ball is dropped from a height of 64 feet. It's height above the earth is the feet given by h(t)=-16t^2+64, where t is the number of seconds after it is dropped
a Find h(1)
b how long does it take the ball to fall to the earth