Help Solving Vectors with Angles - Newbie in Physics

In summary, the first time poster is struggling to solve a problem involving vectors and the u-axis. They are having difficulty understanding the directions and magnitude of the resultant force. They ask for help and the confirmer provides a response explaining that they need to use the v-axis to find the angle of F2 to the u-axis.
  • #1
bh373
5
0
Hello, first timer here. not sure if this should be in physics section or not.. anywayss

I have this question, 2-4 that i have to do for homework but i can't seem to set up the vectors in the correct way to solve b/c the axis/angles are really throwing me off. I'm new at this trying to learn it. i took a picture since its easier to understand than me trying to describe through words.

please help me determine the magnitude of resultant force and its direction.

sorry for my scribbling on the diagram, and please ignore the lightly shaded lines :) THANK YOU
 

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  • #2
For your problem, ignore the axis v except for using it to find the angle between F2 and the u-axis. The problem wants you to find the resultant F1 + F2 relative to the u-axis.
 
  • #3
thanks for the response. so you're saying i need the v-axis to find the angle of F2 to the u-axis? wouldn't that just be 60? i don't see why i'd need the v-axis..
 
  • #4
basically what i cannot understand is :

if the resultant force is somewhere between the U and V axis, how am i supposed to use sine/cosine when the angle will not be 30* or 45*

thanks
 
  • #5
Sine and Cosine are defined for angles 0-360 degrees. Are you having problems calculating trig functions? Remember, you are using a computer to post your homework questions. You can calculate sine and cosine directly or find a table of values for these functions.
 
  • #6
no, i know the values of sin/cos for the commonly used angles. What I am trying to say is while looking at the diagram, wouldn't the resultant force that it is asking me to find the magnitude of, be somewhere between the U and V axis...where angles are not defined? am i just drawing this diagram wrong? for some reason i understand questions involving 3 axis better than these ones that are supposed to be easy...ughhhh
 
  • #7
Pretend the diagram as shown was actually drawn as a mirror image.
Take Vector F1 = 200 lbs < -45 deg
Vector F2 = 150 lbs < +60 deg

Calculate the horizontal and vertical components of F1 and F2 and find the Resultant.
 
  • #8
thank you for the response. I put some time into figuring out the correct answer, this comes much easier now. All i had to do was law of cos to solve for Fr then law of sines to figure out the angle. much easier. thank you
 

FAQ: Help Solving Vectors with Angles - Newbie in Physics

1. What are vectors with angles?

Vectors with angles are quantities that have both magnitude and direction. In physics, they are used to represent the movement or displacement of an object in a specific direction. They are commonly represented by an arrow, with the length of the arrow representing the magnitude and the direction of the arrow indicating the direction.

2. How do I solve vectors with angles?

To solve vectors with angles, you will need to use trigonometric functions such as sine, cosine, and tangent. These functions can help you find the components of the vector, which are the horizontal and vertical parts. Once you have the components, you can use the Pythagorean theorem to find the magnitude of the vector and use inverse trigonometric functions to find the direction.

3. What is the difference between magnitude and direction in vectors?

Magnitude refers to the size or length of a vector, while direction refers to the angle or orientation of the vector. Magnitude is a scalar quantity, meaning it only has a numerical value, while direction is a vector quantity, meaning it has both magnitude and direction.

4. Can vectors with angles be negative?

Yes, vectors with angles can have negative values. A negative vector indicates that it is moving in the opposite direction of the positive vector. However, the magnitude of the vector will always be positive.

5. How are vectors with angles used in physics?

Vectors with angles are used in physics to represent the movement, velocity, acceleration, and forces acting on objects. They are also used in calculations, such as finding the net force on an object or the displacement of an object. Vectors with angles are essential in understanding and analyzing the motion of objects in physics.

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