Physics find angle of inclined plane help?

AI Thread Summary
A block sliding down an inclined plane at a constant velocity of 0.14 m/s has a coefficient of kinetic friction of 0.45, prompting the need to find the angle of inclination. The equations of motion reveal that the net forces in the x and y directions balance out, leading to the conclusion that the angle θ can be calculated using the tangent function. The calculations show that tan(θ) equals 0.45, resulting in an angle of approximately 24 degrees. There is confusion regarding the need for an applied force (Fapp), but it is clarified that the block is moving solely under the influence of gravity and friction. The solution provided is confirmed to be correct.
crosbykins
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URGENT physics find angle of inclined plane! help!?

Homework Statement



A block slides down an inclined plane at a constant velocity of 0.14m/s. The coefficient of kinetic friction is 0.45. What is the angle of inclination?



Homework Equations


Fnetx = Fk -mgsintheta
Fnety = FN -mgcostheta


The Attempt at a Solution



FN-mgcosΘ = 0
FN =mgcosΘ

FN µK –mgsinΘ =0
FN = mgsinΘ/.45

mgcosΘ = mgsinΘ/.45
.45 = mgsinΘ/ mgcosΘ
.45 = tanΘ
tan-1.45 =Θ
24⁰ =Θ

Is this correct? What I don't understand is that shouldn't Fnetx include an Fapp? The question doesn't give a value for Fapp so I don't how you would use it to find the answer.
 
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hi crosbykins! :smile:

(have a smaller theta: θ and try using the X2 icon just above the Reply box :wink:)
crosbykins said:
What I don't understand is that shouldn't Fnetx include an Fapp? The question doesn't give a value for Fapp so I don't how you would use it to find the answer.

yes that looks fine :smile:

i'm not sure what you mean by Fapp …

the block is simply sliding under gravity (any force that pushed it to get it started has been removed)
 


Thank you so much for the help tiny-tim!
 

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