cq_1_172

Phy 231

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: ->->->->->->->->->->->-> :

90 degrees is the angle of the gravitational force

This won't be so if the x axis is inclined as indicated. The 240 degree angle you indicate below, however, is correct and leads you to correct answers.

the y magnitude is greater

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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: ->->->->->->->->->->->-> :

x = magnitude * cos(theta)

x = 49 N * cos(240)

x = -24.5 N

y = magnitude * sin(theta)

y = 49 N * sin(240)

y = -42.44 N

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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: ->->->->->->->->->->->-> :

+42.44 N in the y direction

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• If no other force is exerted parallel to the incline, what will be the cart's acceleration?

answer/question/discussion: ->->->->->->->->->->->-> :

+ 24.5 N in the x direction

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30 mins

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&#Good work. See my notes and let me know if you have questions. &#