In my high school physics course, we had to create an independent lab. I think I've bitten off more than I can chew...

My idea was to make a ramp, then launch a remote control car off of it. Based off of the angle of the ramp, the weight of the car, and knowing the distance I wanted the car to go, I was hoping I would be able to find the initial velocity needed to go this distance.

I realize this is confusing so here is a quick Paint sketch.
http://s1102.photobucket.com/albums/g445/this-is-hard/?action=view¤t=Untitled.png

We haven't learned this yet. Can I even do this?

http://zonalandeducation.com/mstm/physics/mechanics/curvedMotion/projectileMotion/generalSolution/generalSolution.html

KNOWLEDGE IS POWER!

Hmm. I don't think I have enough information to solve this. Blast

The key aspect to doing the calculations you want to do is to separate the velocity (which is a vector quantity, not a scalar quantity) of the car into it's vertical and horizontal vector components. Once you do this you can easily use the vertical component to calculate how long the car will remain in the air, and the horizontal component to calculate how much horizontal distance the car will cover in that time.

You will have to make several assumptions - this is taken for granted in most experiments. You should be able to do this providing you are smart about the sort of assumptions you can make. Simplify this problem down and draw up force diagrams - this will only be as hard as you make it.

I don't have the velocity.



Assumptions do not belong in controlled experiments? But in any case I ended up with this.


Projectile motion laws state:

X=vot*cos(q)
Y=vot*sin(q) – (1/2)gt2

X=vocos(14.93)
Y=vosin(14.93)-(1/2)(9.81)(t2)

X1=v1*t1*cos(14.93)=.966v1t1
350-X1=.966v1+t2

Y1-34.8=.258v1t-490t12

350-.0966v1t1=0.966v1t2

It’s not possible to go any further without knowing either initial velocity or time spent in air. But to find percent difference between theoretical and actual initial velocity, time spent in air will be plugged in.

t1+t2=.51 sec

350=0.966(v1t1+v1t1)
350=0.966 v1 (t1+t1)

v1=350/(.51*0.966)=7.10 m/s

Work through the calculations as if you did. Start with velocity = v, then calculate the horizontal and vertical vector components, then the time spent in the air, then the distance traveled in that time. Now you'll have the distance traveled expressed in terms of v, and from there it's simply a matter of rearranging that to express v in terms of distance traveled.