Projectile Motion / Kinematics Lab (Only 2 Variables Given)

[dimitri194]

Homework Statement

So, our lab entails the students launching a projectile at a certain angle into a cup at a certain distance away. The launcher is 37 cm off of the ground and the cup is 7cm of the ground, so the Dy = 37-7 = 30cm. We will be given the angle in class and will be asked to position the cup at a certain distance. Let's say for example it is 35 degrees.

How could we solve for Dx with only two variables.
Any thoughts?

Thanks.

Homework Equations

tanθ = Vy/Vx

The Attempt at a Solution

I was thinking of using Vx = Vy/tanθ and then possibly substituting something in for Vy from another kinematic equation but that would require time and we are only given measuring tape, no timer.

 

[TaxOnFear]

Hint: we are only given measuring tape.

Welcome to PF!

 

[Redbelly98]

Without knowing the initial speed of the projectile, this problem cannot be solved.