Physics work problem - mastering physics

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SUMMARY

The discussion focuses on calculating the work done by a 15-Newton force using the equation W = F·s·cos(θ). The user initially calculated W as -1838.506 but received feedback from Mastering Physics indicating potential errors in rounding or significant figures. A key point raised is that Mastering Physics requires angle measures in radians, which may affect the calculation of cos(140°). The correct approach involves converting degrees to radians for accurate results.

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  • Understanding of the work-energy principle in physics
  • Familiarity with vector operations and dot products
  • Knowledge of trigonometric functions and their applications
  • Ability to convert between degrees and radians
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  • Review the work-energy theorem in classical mechanics
  • Learn how to perform vector dot product calculations
  • Study the properties of trigonometric functions, specifically cosines
  • Practice converting angles from degrees to radians
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Physics work problem -- mastering physics

Homework Statement


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Find the work W done by the 15-Newton force.

Homework Equations


W=\vec F\cdot\vec s=\left|\vec F\right|\left|\vec s\right|\cos \theta

The Attempt at a Solution


W= 15*cos140*160 = -1838.506
I don't know why mastering physics was telling me "Not quite. Check through your calculations; you may have made a rounding error or used the wrong number of significant figures."
 
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I don't know if you already figured this out, but the only thing I can think of (and it's not really even related to the error you were getting) is that Mastering Physics requires angle measures to be in radians.
 


yes but that shouldn't be affecting the answer though, cos140degree = cos(14/9)pai
Thanks though
 

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