PDA

View Full Version : equilibrium


kimikims
Oct20-04, 08:12 PM
Anyone know what I'm doing wrong? My answers are in Green :)

-----
A 4.4 N weight is in equilibrium under the influence of the three forces acting on it. The F force acts from above on the left at an angle of A with the horizontal. The 5.4 N force acts from above on the right at an angle of 53 degrees with the horizontal. The force 4.4 N acts straight down.

1) What is the magnitude of the force F? Answer in units of N.

5.4 cos 53 degrees = 3.25 N
3.23^2 + 4.4^2 = 29.9225^2
take the square root of 29.9225 = 5.47 N

2) What is the angle A of the force F? Answer in units of N.

tan-1 (4.4/3.25) = 53.5 N

Sirus
Oct20-04, 08:16 PM
You are assuming your force vector triangle is a right-angle triangle. You need to use x/y components or trigonometry to solve the triangle.