Dynamics Homework: Rod BP & AD, Find Velocities

[FChebli]

Homework Statement

:[/B]

Rod BP (20 degrees from horizontal) attached at slider P on rod AD (60 degrees from horizontal), distance between 2 rods = 300 mm, wA = 10 rad/s
(I) Find angular velocity of rod attached at B
(II) Find relative velocity of slider P with respect to the rod on which ot slides.

Homework Equations

:[/B]

v = w r

The Attempt at a Solution

:[/B]

Using the sines rule: BP = 404 mm, AP = 160 mm
vP = 0.16 x 10 = 1.6 m/s

How do I know the directions of vp, vp' and vp/p'?
Is there a specific rule for the direction of vp/p'? Does it have to be perpindiculer to one of the rods?

Thank you!

 

[anathema]

Dear Rod BP,

Thank you for your interesting post. I would like to offer you some guidance in solving your problem.

Firstly, to determine the direction of vP, we can use the right hand rule. Place your right hand on the rod BP with your fingers pointing in the direction of the rotation (from A to B). Your thumb will then point in the direction of vP.

For vP', we can use the same method. Place your right hand on the rod AD with your fingers pointing in the direction of the rotation (from A to D). Your thumb will then point in the direction of vP'.

Lastly, for vP/P', we can use the same method as well. Place your right hand on the rod BP with your fingers pointing in the direction of the rotation (from A to B). Then, place your right hand on the rod AD with your fingers pointing in the direction of the rotation (from A to D). Your thumb will then point in the direction of vP/P'.

I hope this helps you in solving your problem. Remember to always use the right hand rule to determine the direction of velocity in rotational motion. Good luck!