Gravitational force on inclined plane

[Joe91090]

Homework Statement

You place a box weighing 265.5N on an inclined plane that makes a 43.2 degree angle with the horizontal. Compute the component of the gravitaltional force acting down on the inclined plane.

Homework Equations

m x g x cos(degree)

The Attempt at a Solution

265.5 x 9.8 x cos(43.2)

The answer came out incorrect. I think I calculating the wrong force the question confuses me.

 

[Dr.D]

Try drawing the picture. You need to think the geometry through rather than just trying to plug numbers into formulas.

 

[Joe91090]

still very confused do you mean a free body diagram ?

 

[Dr.D]

An FBD should do the job. Perhaps you are confused by the wording. The words, "component ... acting down on the inclined plane" refers to the force normal (perpendicular) to the plane.

 

[Joe91090]

So wouldn't the Normal force be the same as the mass because the inclined plane is holding it up ?

 

[Dr.D]

Which direction is the weight?

 

[Joe91090]

straight down ?

 

[lubuntu]

since when is mass measured in Newtons?

 

[Joe91090]

thats what I am saying wouldn't the Normal force be W=mg ?

 

[Joe91090]

ok so.. 265.5 = m 9.8

m = 27.1N

27.1 x 9.8 x cos(43.2) = 193.6 N = Fn ?

 

[carrotcake10]

m = 27.1N

Newton's aren't a unit of mass

Otherwise, it looks ok to me.

 

[Joe91090]

193.6N isn't the correct answer I am still stumped