Your 'cq_1_19.3' report has been received. Scroll down through the document to see any comments I might have inserted, and my final comment at the end.
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Asst 19 seed 3 word
An object moving in the direction 120 degrees (as measured counterclockwise to the positive x axis) encounters a net force whose direction is 270 degrees.
• Sketch the force and its component in the direction of motion, as well as its component perpendicular to the direction of motion.
answer/question/discussion:
• Will the object speed up, slow down or maintain a constant speed?
answer/question/discussion:
The vector representing your direction of motion should be directed at 120 degrees, the vector representing your net force at 270 degeres.
The angle between these vectors is 150 degrees. So the net force is at 150 degrees relative to the direction of motion.
To be truthful, I believe we need another component to determine anything. We have no actual force or mass so who’s to determine if anything is to happen. I think the object will not speed up but maybe slow down a bit but it could be deflected in some direction.
Imagine that you are facing the direction of motion. Think about how you would perceive the direction of the force. It should be clear from your sketch that force is directed 'backwards and to the left' relative to the direction of motion.
If you sketch a dotted line representing the direction of motion, extending into the second quadrant (at 120 degrees) and back into the fourth quadrant (at 120 degree + 180 degrees = 300 degrees), then the component of the force along this line will clearly be back into the fourth quadrant, in the direction opposite motion. The effect of this component will be to slow the object.
If you sketch another dotted line perpendicular to the first, it will extend into the first quadrant at 120 deg - 90 deg = 30 deg, and into the third quadrant at 30 deg + 180 deg = 210 deg. The component of the force along this line will be directed down into the third quadrant, to the left as perceived by one facing in the direction of motion. The effect of this component will be to accelerate the object toward the left.
• Will the object veer to the right, to the left or maintain straight-line motion?
answer/question/discussion:
This is another good question. Are the objects round or irregular? This would help to determine the possible direction as well but is the collision dead center or glancing blows?
Good question. The problem should have phrased been in terms of the force on a particle, i.e., a point mass. This was the intent, and it should have been clearly stated.
No collision is assumed in this problem, though the source of the force might well be a collision. The problem refers to only one mass, so whatever the source of the force, the question applies to this mass.
If the object is an extended mass, then the question of where on the object the force is exerted becomes important and the solution becomes very challenging. if the line of force is not through the center of mass, then the effect on rotation becomes important.
The object will in any case be slowed and will veer to the left.
• Which is greater in magnitude, the component of the force along the line of motion or the component perpendicular to the line of motion?
answer/question/discussion:
This cannot be determined because of the p = m * a. There isn’t anything to fill in the blanks. The mass of the moving object could be as different as a 10 to 1 ratio or the accelerations could be just different.
The direction of the force, being at 150 degrees relative to the line of motion, is closer to the line of motion than to the direction prependicular to that line.
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20 minutes
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I think this seed had some missing info to be able to determine anything reasonable. It maybe some logic in some future studies that will shed some light on this seed.
See my notes and let me know if you have questions.
The problem is stated as intended and the questions can be answered. It would be fair to say that the course up to this point hasn't really prepared you to answer this question.
Let me know if you don't understand the explanations I've provided, or want further clarification.