# Inclined plane projectile

1. Jun 10, 2013

1. The problem statement, all variables and given/known data
A particle of mass m is projected with velocity of magnitude u at an angle of θ, measured anticlockwise from the line parallel to the plane, from a point (sx,0,sy,0) on a plane inclined at an angle of α measured anticlockwise from the line parallel to the ground. The particle coordinates refer to the particle's initial position (it starts from the plane) relative to the ground (i.e. sx is on an x-axis parallel to the ground, sy is on a y-axis perpendicular to the ground).
Find an expression each for sx and sy in times of time t, given that the particle undergoes no horizontal acceleration and that its only vertical acceleration is -g ms-2.

2. Relevant equations
I don't know. We have to find the equation.

3. The attempt at a solution

Well if the plane were not inclined this would be pretty easy.

$${s_y} = u \cdot \sin{θ} \cdot t + \frac{1}{2} \cdot {a_y} \cdot t^2$$

$${s_x} = u \cdot \cos{θ} \cdot t$$

Where θ is the angle of projection, and ay happens to be -g=-9.8 ms-2 in this case.

But now that the plane is inclined, I really am not sure!

2. Jun 10, 2013

### rude man

Gives me a headache just to figure the problem.

Would be good if the initial velocity were given in terms of v = vx i + vy j + vz k as well as its initial position (x0, y0, z0). Or if it's 2-dimensional (I can't tell from the wording), leave out the z0 and vz k. Then we could compute x(t), y(t) and (if appropriate) z(t).