Vectors Exam1 and Problem Solutions
1. Find A+B+C.
First, we find A+B then add it to vector C.
We find R₁, now we add C to R₁ to find resultant vector.
R₂=A+B+C
2. Find resultant vector.
Since; A+B=E and C+D=E
R=A+B+C+D+E
R=E+E+E=3E
3. A and A+2B vectors are given below. Find vector B
We use vector addition properties.
A+2B-A=2B
To get vector B, we multiply 2B with 1/2.
4. Find resultant vector.
F₁+F₂=5-2=3N
F₁+F₂+F₃=R=3N
5. Which one of the following statements is true?
I. A=B in magnitude
II. A=2C
III. E=2D
IV. A=B
As you can see in the figure given above, A and B are equal in magnitude, so I. is true.
If you multiply C with 2, you get A, this means that II. is also true
E =2D in magnitude but not in direction. Thus; III. is false.
A = B in magnitude but they have different directions, thus; IV is also false.
6.
If α₃<α₂<α₁ and R₁=R₂=R₃, find the relation between F₁, F₂ and F₃.
Decreasing in the angle between forces increases the resultant force.
If α₁=α₂, then R₁>R₂ and F₂>F₃
If α₂=α₃, then R₂>R₃ and F₁>F₂
F₁>F₂>F₃
7. Resultant vector of K, L and M is zero.
Which one of the following statements given below is definitely false?
I. Ky and Ly components are equal vectors
II. K+L=M
III. α=60⁰
I. Ky=-Ly, they are equal in magnitude but opposite in directions, thus they are not equal vectors.I. is false.
II. Magnitude of K+L=M, but directions are opposite, thus II is also wrong.
III: α=60⁰ is possible. III is not exactly false.