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Figure 9-47 (attatched) shows a 0.165 kg cue ball as it bounces from the rail of a pool table. The ball's initial speed is 1.60 m/s, and the angle 1 = 30.0°. The bounce reverses the y component of the ball's velocity but does not alter the x component.
(a) What is theta_2?
(b) What is the change in the ball's linear momentum in unit-vector notation?
I got the physics of part b, the trig of part a is messing me up. I went so far as to make a system:
[tex]v\cos\theta_2=-v\cos\theta_1[/tex]
[tex]v\sin\theta_2=v\sin\theta_1[/tex]
As I thought! The angle must be in the second quadrant... so that means add 90 degrees, right? (And not 180-angle?)
But I don't know how to go from the typical coordinate system used for measuring angles to the funky one shown in the diagram.
(a) What is theta_2?
(b) What is the change in the ball's linear momentum in unit-vector notation?
I got the physics of part b, the trig of part a is messing me up. I went so far as to make a system:
[tex]v\cos\theta_2=-v\cos\theta_1[/tex]
[tex]v\sin\theta_2=v\sin\theta_1[/tex]
As I thought! The angle must be in the second quadrant... so that means add 90 degrees, right? (And not 180-angle?)
But I don't know how to go from the typical coordinate system used for measuring angles to the funky one shown in the diagram.
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