1. The problem statement, all variables and given/known data A rock is thrown upwards at an angle of 35.0° to the horizontal. The rock hits a signpost 15.0 m away at a point 2.00 m above the level from which it was thrown. Calculate the initial velocity of the rock. 2. Relevant equations d = v * t d= displacement, v=velocity, t=time x=x0+v0t+1/2gt^2 x= displacement at t x0 = initial position v0 = initial velocity t=time 3. The attempt at a solution It appears that the x displacement is related: (1) 15=Vx0 x t (vx0 is the initial x-component velocity) because the x velocity is unchanged The y velocity is related: (2) 2=vy0t +1/2gt^2 where vy is the initial y vector component Also: (3) vx = v0 cos 35 (4) vy = v0 sin 35 It appears possible to substitute for vx, vy so that 15= v0 x cos 35 x t 2= v0 x sin 35 x t + 1/2 gt^2 They look like simultaneous equations but I do not obtain the expected result :( Help and advice gratefully received.