Confuse about mg cos@ = R or R cos@ = mg

  • Thread starter Thread starter Scharles
  • Start date Start date
  • Tags Tags
    Cos
AI Thread Summary
In the discussion about forces on an inclined plane, it is clarified that at equilibrium, the normal force (R) balances the component of gravitational force acting perpendicular to the surface, which is mg cosθ. There is an emphasis on the necessity for no acceleration perpendicular to the surface, leading to the conclusion that R = mg cosθ. The participant confirms their forces diagram is correct, and the conversation includes light-hearted commentary on phrasing. Overall, the key takeaway is the relationship between normal force and gravitational force on an incline.
Scharles
Messages
16
Reaction score
0
i am quite confusing about those reaction force...
let say a body is placed on inclined plane with angle @...
at equilibrium, what are the forces that balances each other ??

mg cos@ balanced by R or R cos@ balance mg ??

thanks~
 
Physics news on Phys.org
Hi Scharles! :smile:

(have a theta: θ :wink:)

I always work it out each time …

you know there can be no acceleration perpendicular to the surface …

so the forces perpendicular to the surface must add to zero …

so R balances mgcosθ. :smile:
 
Last edited by a moderator:
Hi Scharles! :smile:
Scharles said:
does my forces diagram draw wrongly ??

No, your diagram looks fine (and very cheerful! :biggrin:).

(btw, it's "is my forces diagram drawn wrongly", or "have I drawn my forces diagram wrongly" or "does my forces diagram look wrong" :wink:)
 
Thread 'Voltmeter readings for this circuit with switches'
TL;DR Summary: I would like to know the voltmeter readings on the two resistors separately in the picture in the following cases , When one of the keys is closed When both of them are opened (Knowing that the battery has negligible internal resistance) My thoughts for the first case , one of them must be 12 volt while the other is 0 The second case we'll I think both voltmeter readings should be 12 volt since they are both parallel to the battery and they involve the key within what the...
Thread 'Struggling to make relation between elastic force and height'
Hello guys this is what I tried so far. I used the UTS to calculate the force it needs when the rope tears. My idea was to make a relationship/ function that would give me the force depending on height. Yeah i couldnt find a way to solve it. I also thought about how I could use hooks law (how it was given to me in my script) with the thought of instead of having two part of a rope id have one singular rope from the middle to the top where I could find the difference in height. But the...
Back
Top