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It's not that the positive x direction is necessarily CCW, it's that a CCW moment about the z-axis is assumed to be positive.goldfish9776 said:Homework Statement
Assuming positive x direction is counterclockwise, then why would the force 50n and 40n are turned clockwise ? (they have negative value)
Homework Equations
The Attempt at a Solution
One quibble: a magnitude is by definition non-negative. Vector components?SteamKing said:These force magnitudes are negative because the force vectors are acting in the negative direction.
That's a fair description.haruspex said:One quibble: a magnitude is by definition non-negative. Vector components?
ok, i understood that when the force 50n fall on 2m(50x2) ( the resultant force vector is in positive k direction , come out of the page . ) . If I do it in the form of 2 X 50 , then it would be in negative k direction , am i right ? can i do in this way ?SteamKing said:It's not that the positive x direction is necessarily CCW, it's that a CCW moment about the z-axis is assumed to be positive.
A positive (CCW) moment could be the result of a positive force multiplied by a positive distance from the axis of rotation or a negative force multiplied by a negative distance from the axis of rotation.
These force magnitudes are negative because the force vectors are acting in the negative direction.
Just like the positive moment direction is assumed to be CCW, positive forces are assumed to act in the positive x or y directions.
It's not a force vector you are calculating here: it's a moment vector. Moment vectors result in rotation either clockwise or counter-clockwise w.r.t. a given axis, and one direction, either CW or CCW, is assumed to be positive. In the example problem from the OP, you are told that positive moments are assumed to be CCW w.r.t. the z-axis coming out of the paper, which also implies that positive forces are in the directions of the x and y axes.goldfish9776 said:ok, i understood that when the force 50n fall on 2m(50x2) ( the resultant force vector is in positive k direction , come out of the page . ) . If I do it in the form of 2 X 50 , then it would be in negative k direction , am i right ? can i do in this way ?
The direction of rotation refers to the direction in which an object rotates around its axis. It can either be clockwise or counterclockwise.
To determine the direction of rotation, you can use the right-hand rule. Simply point your right thumb in the direction of the rotation and curl your fingers. The direction in which your fingers curl is the direction of rotation.
The direction of rotation can be affected by various factors such as the initial velocity and direction of the object, external forces acting on the object, and the shape and orientation of the object.
Clockwise rotation is when an object rotates in the same direction as the hands of a clock, while counterclockwise rotation is when an object rotates in the opposite direction. These directions are also referred to as clockwise or counterclockwise angular velocity.
Yes, the direction of rotation can change. This can happen if there is a change in the forces or external factors acting on the object, or if the object changes its shape or orientation. In some cases, an object can also change its direction of rotation due to internal forces, such as friction or torque.