# Rank the cases from greatest to smallest in order of magnitude

## Homework Statement

http://imgur.com/PUrHBaa
Question 13 in the middle of the page.

Each case in the figure shows an example of force vectors exerted on an object. These forces are all of the same magnitude F_o. Assume the forces lie in the plane of the paper. Rank the cases from greatest to smallest in order of magnitude of the total force. Note: the total force is the vector sum of the individual forces exerted on the objct.

## The Attempt at a Solution

Okay so they say they all have the same magnitude, so I chose value 1 for F_o just to make it simple.

That gives me a magnitude of 1 for case C.

For case B, you have F_y = 1 + sin (5deg) and F_x = cos (5 deg). using (a^2 + b^2 )^(1/2) you get 1.47 N

For case A you have F_y = 1 - sin (5 deg) and F_x = cos (5 deg). Using (a^2 + b^2 )^(1/2) you get 1.35 N

but my book tells me the answer is B>C>A

Is my book just wrong? Or am I doing this wrong? This is simple pythagorean theorem..

Related Introductory Physics Homework Help News on Phys.org
haruspex