The discussion centers on the application of the right hand rule to determine the direction of the angular momentum vector of clock hands moving clockwise. Participants clarify that by curling the fingers of the right hand in the direction of the clock hands, the thumb points perpendicular to the clock face, indicating the direction of the angular momentum vector. Specifically, if the clock is mounted on a wall, the angular momentum vector points outward from the wall, perpendicular to the plane of the clock. This conclusion is essential for understanding angular momentum in rotational dynamics.
PREREQUISITESStudents studying physics, particularly those focusing on mechanics and rotational dynamics, as well as educators seeking to explain angular momentum concepts effectively.
Doc Al said:Do you know what the right hand rule is?
That's right. Make a half-closed fist with your right hand but with your thumb sticking straight out. Align your hand until your fingers curl in the direction that the hands are turning (which is clockwise, of course). The direction of your thumb is the direction of the angular momentum vector.scar123 said:Yes... you have to curl your fingers, and then the thumb points in the direction of the vector?
If you assume your four fingers (excluding the thumb), are sweeping an area in the plane made by the X and Y axis, the thumb will be point in the Z axis. So if there was a clock on your computer screen, the Z axis would be coming out of the screen and into the screen. Now, you have to determine whether the angular momentum is coming perpendicularly out of the plane of the clock and towards you, or in the opposite direction, away from you by seeing which way your four fingers are pointing (They should be moving in a clockwise direction).scar123 said:But your thumb can go in many directions... that doesn't make any sense.
See a doctor... quick! (Just kidding.) Just make a fist with your thumb pointing up. Like you're making a "thumb's up" gesture.scar123 said:But your thumb can go in many directions... that doesn't make any sense.
Describe your final answer with respect to the clock. You should know that when you use the right hand rule, your thumb direction is perpendicular to the plane of your curled fingers. The clock hands move in the plane of the clock, so the angular momentum vector must be perpendicular to the clock face. You have only two choices. Which must it be?scar123 said:Ok I made a fist haha. But then it doesn't make sense of how i should allign it with the clock hands lol... Is it just going to point upward? hhaa
Specify the direction with respect to the clock. (We don't know which way the clock is pointing, so north and east mean nothing here.)scar123 said:north east and north west are my two choices?