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 Homework Statement

A particle moves along a trajectory with velocity whose modulus is constant. At a certain time it is at a point of the trajectory whose radius of curvature is 15 m. At this moment, the modulus of the acceleration is 10 m/s^2. A radar detects that the particle, located 40 m above the ground, moves towards it with velocity v=5 m/s. The radius vector that goes from the radar to the particle forms an angle of 60° with the ground.
Find the angle formed by the velocity and the angular coordinate.
 Homework Equations
 v=(dot r; r dot theta) in polar coordinates
Well, I drew the polar and standard axis centered in the particle and wrote which angles were equal to 60° so I could decompose the velocity. The problem says "moves towards it (the radar) with velocity v=5 m/s, so that's one of the components. But I realised that the velocity "cuts" the angle, so I don't know how I should decompose the velocity. Maybe it's a silly question, but it confuses me.
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