# Rotational Motion and Angular Momentum

Two lightweight rods L = 19.6cm in length are mounted perpendicular to a vertical axle and at 180 degrees to each other (see figure attached).

At the end of each rod is a m = 640Â g mass. The rods are spaced h = 39.6cm apart along the axle. The axle rotates at 28.0rad/s such that the angular velocity vector points upward (+). What angle does the vector angular momentum make with the axle?

I figured out that the component of the total angular momentum along the axle is 1.38 kg*m^2/s in the positive direction. I thought the angle would be 90 deg but I am wrong. All help would be appreciated thanks.

See the attached file.

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#### Solution Preview

I got the same value for total angular momentum. The direction of angular moment is always the same ...

#### Solution Summary

The solution presents a brief explanation of the theory of the inertia and angular velocity equation to explain how the direction is affected in the rotational motion problem given by the asker.