Moment about a point in an incline plane

AI Thread Summary
The discussion focuses on calculating the moment produced by a force acting on an inclined plane about a specific point. The force, F, is given as 460 N, acting perpendicular to the plane. The user attempts to compute the moment using position vectors and unit vectors but receives feedback that their answer is incorrect. There is confusion regarding the magnitude of the force and its components in the calculations. Clarification on the correct approach to find the moment and the proper use of vector components is sought.
Robb
Messages
225
Reaction score
8

Homework Statement



Probs._448_49.jpg


Force F = 460 N acts perpendicular to the inclined plane

Determine the moment produced by F about point A.
Enter the x, y, and z components of the moment separated by commas.

Homework Equations

The Attempt at a Solution



r(CA)=4j-3k
u(CA)=4/5j-3/5k

r(CB)=-3i+4j
u(CB)=-3/5i+4/5j

u(CA) x u(CB)=1.28i+.36j+.48k
F=460(1.28i+.36j+.48k)=589i+166j+221k

r(CA) x F=1382i-1767j-2356k

masteringengineering.com says the answer is wrong. Please help!
 
Physics news on Phys.org
Robb said:
F=460(1.28i+.36j+.48k)=589i+166j+221k
Is the magnitude of this force 460 N?
 

Thread 'Errors and significant figures'

I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
View full post »
Thread 'A cylinder connected to a hanging mass'

Thread 'A cylinder connected to a hanging mass'

Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
View full post »

Similar threads

How Does Angular Velocity of a Rolling Cylinder Change Over Time?
Replies
5
Views
2K
Find Moment Around A with 3D Vectors: B & C
Replies
3
Views
1K
What is the Moment Produced by a Perpendicular Force on an Inclined Plane?
Replies
8
Views
4K
Statics, bike on inclined plane
Replies
12
Views
5K
Inclined Plane Rotational Motion
Replies
27
Views
4K
How Do You Calculate the Total Moment of Forces on a Plane?
Replies
1
Views
2K
Block Sliding Down Inclined Plane with Pulley and Friction
Replies
5
Views
8K
Confusion about Coulomb's Law and 3 Point Charges
Replies
2
Views
3K
Analyzing Force & Motion on an Inclined Plane
Replies
12
Views
2K
Why is this length included when finding moment about an axis
Replies
4
Views
2K

Hot Threads

Recent Insights

Back
Top