How Do You Calculate Net Force Components on a Tilted Surface?

  • Thread starter STEMucator
  • Start date
  • Tags
    Forces
In summary: When you try to solve for the net force using component form (without tilting the force), you get two different angles depending on which side of the vector you are looking at (x or y). The angle between the force and the x-axis is 60 degrees when looking at it from the vector's perspective, but when looking at it from the y-axis it is 75 degrees.
  • #1
STEMucator
Homework Helper
2,076
140

Homework Statement



Three forces are exerted on an object placed on a tilted floor: http://gyazo.com/53e480ef2b77acc48de89d4cb4ba9e5c

a) What is the component of the net force parallel to the floor?
b) What is the component of the net force perpendicular to the floor?
c. What is the magnitude and direction of the net force?

Homework Equations


The Attempt at a Solution



I had a few questions about this problem.

I could take the usual route by defining North and East to be positive (the book always wants me to define +x and +y to be positive) and then tilting the vector ##\vec{F}_3## so that it matches up with with the axes. The y component of ##\vec{F}_3## would form a 30 degree angle in-between the two vectors:

http://gyazo.com/2446737a5ca979a1cd7c8d7d50a60682

I could then proceed to solve for the net forces in the x (parallel) and y (perpendicular) directions and then use them to find the magnitude and direction of the net force.

My question is what if I didn't take this route? What if I use component form to solve for the net force instead WITHOUT tilting the force ##\vec{F}_3##. Would the angle between ##\vec{F}_3## and the positive x-axis simply be 60 degrees?

That would change my components from the other route I took. Would that not change the overall answer?
 
Physics news on Phys.org
  • #2
I'm unclear on your alternative method. Please post the algebraic details for both.
 
  • #3
haruspex said:
I'm unclear on your alternative method. Please post the algebraic details for both.

Here's how I figured the problem at first:

http://gyazo.com/2446737a5ca979a1cd7c8d7d50a60682
http://gyazo.com/ab7d1f7521c310797a2158ee88228854
http://gyazo.com/920a635d7e9efae36cbb3883837b4988

The book provided this following example in the text, which uses a slightly different method by the looks of it. Though in the book's example they did something pretty weird, which in turn led to this confusion:

http://gyazo.com/09d55ca78facd6a85ea2682a9a6500cd

I understand the argument as to why the angle is 75 degrees and how they got the components. What I don't understand is why they did this instead of tilting the vector?

When I tried to apply this method to the question, I got confused as I would have to use a 60 degree angle, which looks like it's going to change the overall answer since it will change some components, namely ##\vec{F_3}_{x}## and ##\vec{F_3}_{y}##.

EDIT : Never mind I figured out what was going on.
 
Last edited:

FAQ: How Do You Calculate Net Force Components on a Tilted Surface?

1. What are the three forces acting upon an object?

The three forces acting upon an object are gravitational force, normal force, and frictional force.

2. How does gravitational force affect an object?

Gravitational force is a force of attraction between two objects with mass. It causes objects to accelerate towards each other and is dependent on the masses of the objects and the distance between them.

3. What is normal force and when does it occur?

Normal force is the force exerted by a surface on an object in contact with it. It acts perpendicular to the surface and prevents objects from passing through each other. It occurs whenever an object is in contact with a surface.

4. What factors affect the amount of frictional force on an object?

The amount of frictional force on an object is affected by the type of surface the object is on, the weight of the object, and the roughness of the surfaces in contact.

5. How do these forces interact with each other on an object?

These forces can either work together or in opposite directions on an object. The net force on an object is the vector sum of all the forces acting upon it.

Back
Top