What is the magnitude of the sum of the following vectors?

AI Thread Summary
The discussion revolves around calculating the magnitude of the sum of three vectors: A, B, and C. The user initially sums the components incorrectly, leading to an incorrect magnitude calculation of 9.27. Other participants point out the need to carefully recheck the vector addition for accuracy. The correct approach involves accurately summing the i, j, and k components before applying the magnitude formula. The conversation emphasizes the importance of precise calculations in vector addition.
Mdhiggenz
Messages
324
Reaction score
1

Homework Statement



What is the magnitude of the sum of the following vectors?

A= i +5j -k

B= 4i-j-5k

C= -i+j


Homework Equations






The Attempt at a Solution



What I did was I added i+4i-i to get 5i, I also added 5k+j-5 to get 5j, likewise for k to get -6k

and did the squareroot of (25+25+36) to get squareroot of 86 or 9.27 however that is not the right answer. What am I doing wrong?

Thank you
 
Physics news on Phys.org
Mdhiggenz said:
What I did was I added i+4i-i to get 5i,
Redo that addition.
 

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

Equation for Fourth Force and its Line of Action?
Replies
6
Views
1K
Magnitude and direction of k vector
Replies
6
Views
3K
Calculate electric force using Coulomb's law (vector components are the struggle)
Replies
3
Views
1K
Finding Vector Angle using cosine law
Replies
13
Views
2K
How can I find the length of this pole?
Replies
1
Views
2K
Find direction from three displacement vectors?
Replies
1
Views
3K
Where am I going wrong with this vector addition?
Replies
1
Views
1K
Perpendicular Component of Vector A in the Plane of A and B
Replies
5
Views
2K
How Is Kinetic Energy Calculated from Force and Displacement?
Replies
3
Views
7K
Adding Vectors-Calculating Magnitude and Location
Replies
6
Views
2K

Hot Threads

Recent Insights

Back
Top