phy 121
Your 'cq_1_17.2' 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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A 5 kg cart rests on an incline which makes an angle of 30 degrees with the horizontal.
• Sketch this situation with the incline rising as you move to the right and the cart on the incline. Include an x-y coordinate system with the origin centered on the cart, with the x axis directed up and to the right in the direction parallel to the incline.
The gravitational force on the cart acts vertically downward, and therefore has nonzero components parallel and perpendicular to the incline.
Sketch the x and y components of the force, as estimate the magnitude of each component.
What angle does the gravitational force make with the positive x axis, as measured counterclockwise from the positive x axis? Which is greater in magnitude, the x or the y component of the gravitational force?
answer/question/discussion: ->->->->->->->->->->->-> :
I made a sketch of this scenario, but feel like I am missing some information to solve this. I’m sure this isn’t really the case though- I’m just not sure what to do next.
We have the angle of the incline (30 degrees) and the weight of the cart which is 5 kg.
The only x, y coordinates I thought we could use for this would be 0,0 as that is the point from where the my incline starts to rise.
I think the angle the gravitational force makes with the positive x axis is 160 degrees. I think it is this because I took half of a circle (180 degrees) and subtracted the initial 30 degrees.
I think that it depends on how far the cart travels to whether or not the x or y component of the gravitational force is greater in magnitude.
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• Using the definitions of the sine and cosine, find the components of the cart's weight parallel and perpendicular to the incline.
answer/question/discussion: ->->->->->->->->->->->-> :
I know that to find sine we use the opposite angle/hypotenuse. The only numbers from the original problem were 5 kg and 30 degrees. Normally when solving for sine and cosine I thought the numbers we used were more so lengths.
To find the cosine we would use adjacent/hypotenuse.
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• How much elastic or compressive force must the incline exert to support the cart, and what is the direction of this force?
answer/question/discussion: ->->->->->->->->->->->-> :
I looked through the book and I found the formula F=kx was used to determine elastic force. I’m not sure if this is correct or where I would proceed from this point to solve.
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• If no other force is exerted parallel to the incline, what will be the cart's acceleration?
answer/question/discussion: ->->->->->->->->->->->-> :
I think I would need to know the velocity to solve for the carts acceleration. Would we use the formula 1/2m * v to solve for that or would we just assume that the cart’s acceleration is simply 9.8 m/s^2???
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45 minutes
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I found this assignment to be particularly challenging. It seemed like a lot of this information was really new or else I missed a previous assignment that would have provided me with the necessary background knowledge to correctly work through these questions.
I'm tempted to insert some notes, but I think the link below will be clearer.
&#Please compare your solutions with the expanded discussion at the link
Solution
Self-critique your solutions, if this is necessary, according to the usual criteria. Insert any revisions, questions, etc. into a copy of this posted document. Mark any insertions with &&&& so they can be easily identified. &#