Question

HELP PLEASE!

Let’s suppose you throw a ball straight up with an initial speed of 50 feet per second from a height of 6 feet.

a. Find the parametric equations that describe the motion of the ball as a function of time.
b. How long is the ball in the air?
c. Determine when the ball is at maximum height. Find its maximum height.

Answer 1

we can use gravity?

Answer 2

no i dont think so... see what i got for a, was:
y=-16t^2 + 50t + 6

Answer 3

plug in y=-6

Answer 4

i dont get it

Answer 5

dy/dt=v,plug in v = 0

Answer 6

Parametric equations in this case use t for time.

May I recommend a tutorial?
http://www.khanacademy.org/math/precalculus/v/parametric-equations-1

Answer 7

c)
dy/dt=v,plug in v = 0

Answer 8

so what i wrote for A wrong?

Answer 9

Or are you just trying to get a quick answer? That video I linked is so you'll understand how to handle any such similar parametric equation, like the one you're asking about in fact.

Also, it really helps to list givens...
\[a_g=32 ft/s^2 \]
\[v_0=50 ft/s\]
\[x=6 ft\]

Answer 10

both but mostyl trying to understand it.

Answer 11

You're doing two planes. movements in the x-axis and movements in the y-axis.
These are both changing with respect to time (cursive 't' symbol)

now ask yourself:

The initial velocity is which direction? +x (right), -x (left), +y (up), -y (down)
Gravity is in which direction?
What is the initial 6ft position relative to the axes?

Answer 12

so this is what i originally got as far...