Finding the Direction of a Puck's Velocity on an Air Hockey Table

[mac227]

Homework Statement

A puck is moving on an air hockey table. Relative to an x, y coordinate system at time t = 0 s, the x components of the puck's initial velocity and acceleration are v0x = +3.3 m/s and ax = +4.5 m/s2. The y components of the puck's initial velocity and acceleration are v0y = +6.4 m/s and ay = -3.2 m/s2. Find (a) the magnitude v and (b) the direction θ of the puck's velocity at a time of t = 0.50 s. Specify the direction relative to the +x axis

Homework Equations

The Attempt at a Solution

the magnetude v is 7.2 m/s but I cannot find the direction. When i plug into formulas none of my answers are correct: initial y velocity= (7.2) sin θ

 

[tiny-tim]

welcome to pf!

hi mac227! welcome to pf!

the magnetude v is 7.2 m/s but I cannot find the direction.

i don't get 7.2

in future, please show your full calculations …

then we can see where you've gone wrong

initial y velocity= (7.2) sin θ

initial?

and why not use v_y/v_x = tanθ ?