Is This Equation Correct for Horizontal Projection?

[Physicsisfun2005]

I think this physics problem deals only with horizontal projection...let me know what you think:

A block slides off a horizontal surface with speed Vo. Write an expression relating y, distance fallen, to X, the horizontal distance traveled.
i think i can use the horizontal proj. equations:

R=VoT (I think you can substitute X for R)

h=.5gt^2 (I think you can substitute y for h)

I get a combined equation of y=.5g(x/Vo)^2..which simplfied b/c .5g=4.9
Y/4.9=(X/Vo)^2...which i think can simplify to the
(square root of y/4.9)=X/Vo

 

[chroot]

Originally posted by Physicsisfun2005
I get a combined equation of y=.5g(x/Vo)^2

That is correct, and I would leave it in exactly that form. The rest of your "simplifications" really just seemed to make a mess of it. You are asked to express y as a function of x (or x as a function of y), and that's exactly what you've done. You're finished!

- Warren

 

[M98Ranger]

Yes, you are correct. The problem only deals with horizontal projection, as the block is sliding off a horizontal surface. Your approach of using the horizontal projection equations is correct. By substituting X for R and y for h, you can arrive at the expression y=.5g(x/Vo)^2, which can be simplified to (square root of y/4.9)=X/Vo. This equation relates the distance fallen, y, to the horizontal distance traveled, X. Great work!