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nat89
Nov 3, 2007, 09:14 PM
I need help answering these word problems... I don't get it at all. I don't know how to draw the picture and label it with info that is given.
I have to use the following equations to solve for it...
variable with subscore of x or y is the direction. X for horizontal and y for vertical...
X:
vx = vox + axt

vx2 = vox2 + 2ax (x-xo)

x = xo + vox t + 1/2 ax t2

Y:

vy = voy + ayt

vy2 = voy2 + 2ay (y-yo)

y = yo + voy t + 1/2 ay t2

the x, y, ox, and oy are subscripts except for one in parenthesis but o is always subscript for initial and the 2 is power.

1. a tiger jumps horizontally off a 3 meter tall rock lands on 2 meters from the base of the rock.how much time did the tiger spend in the air?

2. what was the initial velocity of the tiger in problem 1?

3. an arrow is shot horizontally with an initial velocity of 120 m/s. how much time does the arrow spend in the air before hitting the ground?

4 how far did the arrow travel in problem 3?

I just want to know how to draw the picture and what is given for x or y?? Or possibly solve it, but if it takes too much time don't have to... thanks if you help or even if you don't :)
sorry if I do something wrong I'm knida new to this... :)

terryg752
Nov 6, 2007, 05:45 AM
What you have to understand is:

1. Horizontal velocity remains unchanged - acceleration is zero
2. Vertical acceleration is downward, with value equal to g (gravity)
3. Think of the verticle and horizontal motion in isolation from each other. This will
help you figure out the solutions.

4. For example, in the first case find the expression for time to fall from the height of 3 meters, and this should equal the time to travel 2 meters horizontally.

5. When something starts horizontally, the verticle component of initial velocity is obviously zero.

terryg752
Nov 6, 2007, 12:15 PM
Another Hint:

Ask a friend to throw a ball horizontally from some height, while you observe the path of the ball.

This will help you visualise the curve.