I know that the formula for work is
W=fd x cos. of theta
When would it be fd x sin of theta?
2006-12-17 06:34:02 · 5 answers · asked by classicrockrox 3 in Science & Mathematics ➔ Physics
you would use sine rather than cosine if theta was defined as the angle between the applied force and the perpendicular to motion, rather than the angle between the force and the motion
2006-12-17 07:00:45 · answer #1 · answered by Physics Major 4 · 0⤊ 0⤋
=1
2006-12-17 06:59:02 · answer #2 · answered by FooFoo 1 · 0⤊ 0⤋
Work is only done in the direction of the force and has to be parallel to the surface. so, if you are pulling a box along a floor, only the horizontal component of the force (cos of theta) would be used to calculate work (W = Fd). i guess if a person could somehow walk along a wall and pull a box along the vertical wall, sin of theta would be used since the surface would be a vertical surface. Sin is used to find the y-component or vertical part of a force. Cos is used to find the x-component or horizontal part of a force. You will probably not use sin of theta because it isn't likely that you will be applying a force to an object on a wall.
2006-12-17 06:53:37 · answer #3 · answered by nanabanana 2 · 0⤊ 0⤋
Well, the obvious answer is when cos(theta)=sin(theta), i.e., when theta=pi/4=45 degrees. However, consider the situation when pushing an object along a surface. If the object moves at a fixed velocity, then the only work being done is that against friction. What is the frictional force? It is the coefficient of friction multiplied by the normal force at the frictional surface, i.e., it is
Fric=mu*F*sin(theta),
where mu is the coefficient of friction. So, if the only work being done is due to the friction resulting from the applied force at a frictional surface, then the work done will be
w=F*d*sin(theta)
when the coefficient of friction is equal to 1.
2006-12-17 10:07:53 · answer #4 · answered by Dr.T 4 · 0⤊ 0⤋
Work is force multiplied by the distance over which the force acts.
W = Fd
If it happens that the work occurs in such a way that it is necessary to take a trigonometric component of force then you would then need to use the appropriate trig into account.
Does this help any?
2006-12-17 07:02:53 · answer #5 · answered by Anonymous · 0⤊ 0⤋
If Θ is the angle between the direction of the force and the direction of travel, you use cos Θ.
Cos Θ = 1 when Θ = 0, i.e. the force is acting in the direction of travel. If Θ = 90 dec., cos Θ = 0 and so no work is done
2006-12-17 06:42:53 · answer #6 · answered by JJ 7 · 0⤊ 0⤋
Isn't w=f/t the equation for work
2006-12-17 07:23:59 · answer #7 · answered by ZelosWilder 5 · 0⤊ 0⤋