What are the other forces acting on ##dm## in addition to gravity?

In summary, the conversation discusses the process of finding the tangential acceleration of a rotating object using energy conservation and torque. The conversation also mentions the presence of additional forces, such as tension, that need to be considered in the calculation. The discrepancy between the two methods of calculation is also mentioned.
  • #1
Vivek98phyboy
34
5
Homework Statement
A uniform rod of length L pivoted at its upper end hangs vertically. It is displaced through an angle of 60° and then released. Find the magnitude of the force acting on a particle of mass 'dm' at the tip of the rod when the rod makes an angle of 37° with the vertical.
Relevant Equations
Tangential acceleration of tip(dm), a= L𝛂
After solving using energy conservation, I found the angular velocity at 37° to be omega=2.97/(L)^½

IMG_20200806_184138.jpg


Tension and the weight (dm)g are the two forces acting on the tip dm
To find the resultant force, I resolved the centripetal force and tangential force to find the centripetal force as
F= (dm)(L)(omega)²
and tangential force as (dm)(g)sin37°.
This would leave me with a tangential acceleration of 5.9 m/s²
But when I calculated it using torque, I found the tangential acceleration to be 8.82m/s² and that is the solution given in my book

What am I doing wrong while resolving the forces?

I would also like to know what would be the forces provided by the part of rod that is above 'dm'?
 
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  • #2
The force of gravity is not the only force on ##dm## that has a tangential component. The force that "binds" ##dm## to the rod also has a tangential component.
 

1. What is the definition of gravity?

Gravity is a natural phenomenon by which all objects with mass are brought towards each other. It is one of the four fundamental forces of nature, along with electromagnetism, the strong nuclear force, and the weak nuclear force.

2. What are the other three fundamental forces?

The other three fundamental forces are electromagnetism, the strong nuclear force, and the weak nuclear force. Electromagnetism is responsible for the interaction between electrically charged particles, while the strong nuclear force holds the nucleus of an atom together. The weak nuclear force is responsible for certain types of radioactive decay.

3. How do these forces interact with gravity?

These forces do not directly interact with gravity. However, they can affect the motion of objects and particles, which can in turn affect the force of gravity acting on them. For example, the strong nuclear force can affect the mass of an object, which would then affect the force of gravity acting on it.

4. Are there any other forces besides the four fundamental forces?

Yes, there are other forces that can act on objects, such as friction, tension, and air resistance. However, these forces are not considered fundamental forces as they can be explained by the four fundamental forces.

5. How do these additional forces impact the force of gravity?

These additional forces can either increase or decrease the force of gravity acting on an object. For example, friction or air resistance can decrease the force of gravity by slowing down the object's motion, while tension can increase the force of gravity by pulling on the object in a certain direction.

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