How do i solve this physics problem that contains vectors

In summary, the displacement vectors A and B both have a magnitude of 3.00, with Vector B lying on the y-axis and Vector A having a 30 degree angle from the positive X axis. When adding vectors, the components should be separated and added together to make the new vector. For example, A+B would have a magnitude of 3 and a theta of 30 degrees.
  • #1
baseball2233
1
0

Homework Statement


Each of the displacement vectors A and B have a magnitude of 3.00.
Vector B lies on the y-axis and Vector A has a 30 degree angle from the positive X axis.

a) A+B
magnitude = ?
θ = ?

(b) A-B
magnitude = ?
θ= ? °

(c) B - A
magnitude =?
θ= ? °

(d) A - 2B
magnitude =?
θ= ? °


Homework Equations





The Attempt at a Solution



I really don't have a clue how to figure this out, any help would be great
 
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  • #2
The idea is, when adding vectors, to separate them into their components, and then add those components to make the new vector. You know [tex]\vec{B}=3\hat{y}[/tex], and [tex]\vec{A}=3\cos{30}\hat{x} + 3\sin{30}\hat{y}[/tex], at least you should know that. So then, for example, [tex]A + B = 3\cos{30}\hat{x} + (3 + 3\sin{30})\hat{y}[/tex]. Make sense? See where you can get using this method.
 
  • #3


I would suggest approaching this problem by breaking down the given information into smaller, more manageable pieces. First, let's draw a diagram to visualize the situation.

We know that Vector B lies on the y-axis, which means it has a 90 degree angle from the positive X axis. Vector A has a magnitude of 3.00 and an angle of 30 degrees from the positive X axis. This can be represented on a graph as shown below:

Now, let's look at the given equations and try to solve for the unknown values.

a) A+B
To find the magnitude of A+B, we can use the Pythagorean theorem: c^2 = a^2 + b^2. In this case, a and b represent the x and y components of the vectors A and B respectively. Using basic trigonometry, we can find the x and y components as follows:

a = Acos(30) = 3cos(30) = 2.598
b = Bsin(90) = 3sin(90) = 3

Plugging these values into the Pythagorean theorem, we get:
c^2 = (2.598)^2 + 3^2 = 6.744
c = √6.744 = 2.596

Therefore, the magnitude of A+B is 2.596. To find the angle θ, we can use the inverse tangent function (tan^-1) on the ratio of the y and x components:

θ = tan^-1(b/a) = tan^-1(3/2.598) = 51.34°

b) A-B
Using the same method as above, we can find the magnitude and angle of A-B as follows:

a = Acos(30) = 3cos(30) = 2.598
b = -Bsin(90) = -3sin(90) = -3

Plugging these values into the Pythagorean theorem, we get:
c^2 = (2.598)^2 + (-3)^2 = 6.744
c = √6.744 = 2.596

Therefore, the magnitude of A-B is also 2.596. To find the angle θ, we can use the inverse tangent function (tan^-1) on the ratio of the y and x components:

θ = tan^-1
 

Related to How do i solve this physics problem that contains vectors

What are vectors and how do they relate to physics?

Vectors are mathematical quantities that have both magnitude and direction. In physics, they are used to describe the motion and forces of objects.

How do I add or subtract vectors?

To add or subtract vectors, you must first break them down into their x and y components. Then, add or subtract the components separately to get the resulting vector.

How do I find the magnitude and direction of a vector?

The magnitude of a vector is its length and can be found using the Pythagorean theorem. The direction of a vector can be found using trigonometric functions such as sine, cosine, and tangent.

Can vectors be multiplied?

Yes, vectors can be multiplied through a process called vector multiplication. There are different types of vector multiplication, such as dot product and cross product, which have different applications in physics.

What are some common mistakes when working with vectors in physics problems?

Some common mistakes include forgetting to convert units, not considering the direction of the vectors, and making calculation errors when adding or subtracting components. It is important to carefully read and understand the problem and double-check all calculations to avoid these mistakes.

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