he tune-up specifications of a car call for the spark plugs to be tightened to a torque of 47 N⋅m . You plan to tighten the plugs by pulling on the end of a 25-cm-long wrench. Because of the cramped space under the hood, you'll need to pull at an angle of 115 ∘ with respect to the wrench shaft. You may want to review (Page

Respuesta :

Answer:

207.4 N

Explanation:

The torque [tex]\tau[/tex]  on a body is

[tex]\tau = r* F[/tex]  where r is the radius vector from the point of rotation to the point at which force F is applied.

The product of r and F is equal to the product of magnitude of r and F multiplied by the sine of angle between both vectors.

Therefore, torque is also given by

[tex]\tau = rF\sin \theta[/tex]

Where [tex]\theta[/tex] is the angle between r and F.

Use the expression of torque.

Substitute L for r in the equation [tex]\tau = rF\sin \theta[/tex]

[tex]\tau = LF\sin \theta[/tex]

Where L is the length of the wrench.

Making F the subject

[tex]F = \frac{\tau }{{L\sin \theta }}[/tex]

Force required to pull the wrench is given as,

[tex]F = \frac{\tau }{{L\sin \theta }}[/tex]

Substitute [tex]47{\rm{ N}} \cdot {\rm{m}}[/tex]  for [tex]\tau[/tex], 25 cm for L, and 115o for [tex]\theta[/tex]  

[tex]\begin{array}{c}\\F = \frac{{47{\rm{ N}} \cdot {\rm{m}}}}{{\left( {25{\rm{ cm}}} \right)\sin {{115}^{\rm{o}}}}}\left( {\frac{{1{\rm{ cm}}}}{{{{10}^{ - 2}}{\rm{ m}}}}} \right)\\\\ = 207.435{\rm{ N}}\\\\ \approx 207.4{\rm{ N}}\\\end{array}[/tex]  

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