what are x and y supposed to be?

Question

I got some advice on here about a question on projectile motion on a slanted surface, but I have no idea what the variables x or y are supposed to be. are they distance of x and distance of y? i am confused. here is the advice:

y = v_y0t -1/2 gt² and x = v_x0t or y in terms of x:

y = (v_y0/v_x0)x - 1/2 (g/v_y0²) x²

The incline is given as y = x(tan(φ)) where φ is the angle of the incline.

So you have a quadratic equation in x:

(g/(2v_x0²)) x² + ((-v_y0/v_x0) + tanφ)x = 0 Note that x = 0 is solution. factor out an x and solve.

Note that the ratio of v's is tanθ₀ and v_x0 = v₀cosθ₀

Answer 1

y is up. x is across as in the usual coordinate directions. v₀ is v at time = 0 g is 9.8 m/s² downwards (so it is negative) You solve for x and plug that value in to solve for y.

Up the incline will be sqrt(x^2 + y^2)