For the slider-crank mechanism shown, let R = 20 mm, L = 80 mm, and H = 38 mm.Figure P6.69...

For the slider-crank mechanism shown, let R = 20 mm, L = 80 mm, and H = 38 mm.

Figure P6.69

Determine the angular velocity of the crank OA when θ = 20° and the slider is moving downward at 15 m/s.