Why are there no force resolutions at ##30^0##?

  • Thread starter Benjamin_harsh
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In summary: The weight force, ##F_{g}##, which is equal to mg.sinθ, and the normal force, ##F_{N}##, which is equal to mg.cosθ, were resolved at the angle ##θ## instead of the angle ##30^0##. The sum of the forces in the x-direction, ##\sum F_{X}##, is equal to the weight force, ##F_{g}##, and the acceleration in the x-direction, ##a_{x}##, is equal to ##10.sin(30)
  • #1
Benjamin_harsh
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5
Homework Statement
A 10 kg box rest on a 30 degree incline and begins to slide down. What is the acceleration if no friction is present?
Relevant Equations
##m.a_{x} = mg.sinθ## , ##a_{x} = 10.sin(30)##
244316


There is a component the weight force that accelerates the box downwards, ##F_{g}##, which is equal to mg.sinθ of below triangle.

##F_{g}= mg.sinθ##

##F_{N}= mg.cosθ##

##\sum F_{X} = F_{g}##

##m.a_{x} = mg.sinθ##

##a_{x} = 10.sin(30)##

##a_{x} = \large \frac {1}{2}##

##a_{x} = 5 \large \frac {m}{sec^2}##

Why there is no force resolutions at ##30^0##? I mean why resolutions taken at below the box?
 
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  • #2
Benjamin_harsh said:
Why there is no force resolutions at ##30^0##? I mean why resolutions taken at below the box?

I don't understand your question.
 
  • #3
PeroK said:
I don't understand your question.

Why did we resolve forces at ##θ## instead of ##30^0##?
 
  • #4
Benjamin_harsh said:
Why did we resolve forces at ##θ## instead of ##30^0##?

##\theta = 30°##
 
  • #5
PeroK said:
##\theta = 30°##
Why did resolve forces near body instead of corner of the triangle?
 
  • #6
Benjamin_harsh said:
Why did resolve forces near body instead of corner of the triangle?

It's usual to show the resolution of forces where they apply. I.e. on the block itself. There are no relevant forces acting at the corner of the triangle. There's nothing going on there.
 
  • #7
PeroK said:
It's usual to show the resolution of forces where they apply. I.e. on the block itself. There are no relevant forces acting at the corner of the triangle. There's nothing going on there.
Thank you
 

1. Why is there no force resolution at 30 degrees?

The reason there is no force resolution at 30 degrees is because the force resolution equation involves taking the sine and cosine of the angle between two forces. At 30 degrees, the sine and cosine values are both equal to 0.5, which means the resolution of forces would result in an infinite number of solutions.

2. Can force resolutions be calculated at other angles?

Yes, force resolutions can be calculated at any angle as long as the angle is not 30 degrees or any other angle where the sine and cosine values are equal. In these cases, the force resolution equation would result in an infinite number of solutions.

3. How do force resolutions help in solving problems?

Force resolutions help in solving problems by breaking down a single force into two components that act in different directions. This allows for a more manageable analysis of forces in a system, making it easier to determine the overall net force.

4. Are force resolutions necessary for every problem involving forces?

No, force resolutions are not necessary for every problem involving forces. They are mainly used when there is an angle between two or more forces, and the goal is to determine the net force acting on an object. In some cases, it may be easier to analyze forces without using force resolutions.

5. Can force resolutions be used in real-life situations?

Yes, force resolutions are commonly used in real-life situations, especially in engineering and physics. They are used to analyze the forces acting on structures, machines, and other objects to ensure they are stable and can withstand external forces. Force resolutions are also used in navigation and aviation to calculate the net force acting on an aircraft or ship.

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