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## Homework Statement

If it takes a horizontal force of 300N to push a stalled automobile along a level road at a constant speed, how much qwork must you do to push this automobile a distance of 5.0m?

## Homework Equations

W = F x [tex]\Delta[/tex]x

## The Attempt at a Solution

I used the above formula W = (300N)(5.0m) = 1.5 x 10

^{3}J, however, in checking my work with the solutions manual, they used the formula W=F

_{s}COS[tex]\theta[/tex]. Both formulas come upi with the same answer.

I do not understand why the authors chose to use the W=F

_{s}COS[tex]\theta[/tex] formula because I thought that this formula was only used when "the motion of the particle and the force are not along the same line" (from the book), such as "along some arbitrary curved path."

Is this a case where W = F x [tex]\Delta[/tex]x can only be used in cases where the motion of the particle and the force are along the same line but W=F

_{s}COS[tex]\theta[/tex] can be used in either case?