# Homework Help: Projectile Help

1. Nov 4, 2004

### Crouch

For a physichs project I had to build a trebuchet. I measured how for it shot, and how long it took. After some calculations I got:
Vi in the X= 6.258
VI in the y= 6.64
Accel in X= 0
Accel in Y= -9.8
Distance in the X= 4.8
Distance in the Y= 2.25
Time in the X= 1.36
Time In the Y= .68

Now after that I am supposed to pick different points on the arc and measure the Velocity in the Y and X. Im not sure what distance to use? For instance if I wanted to measure the velocity at .1 seconds in the arc on the X and Y, what would I use?

2. Nov 4, 2004

### Crouch

Someone Please Help Me. I can only stay online another 40 minutes, and I need this done tonight.

3. Nov 4, 2004

### maverick280857

The velocity versus time relationships are:

$$v_{x} = v_{0}\cos\alpha$$
$$v_{y} = v_{0}\sin\alpha - gt$$

In your case.

$$v_{i,x} = v_{0}\cos\alpha$$
$$v_{i,y} = v_{0}\sin\alpha$$

4. Nov 4, 2004

### Skomatth

velocity at any point = vi+at

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