Solving a Homework Statement: Finding Forces and Distances

  • Thread starter Thread starter StrawHat
  • Start date Start date
  • Tags Tags
    Forces Homework
AI Thread Summary
The discussion revolves around solving a homework problem involving forces and distances in a physics context. The user successfully calculated the radius (r = 1.323m) and angle (θ = 41.41°) using relevant equations. They derived the tensions in the upper and lower strings (Tupper = 135.45N, Tlower = 77.3N) while considering the forces acting in both the x and y directions. A clarification was made regarding the direction of the gravitational force, concluding that it does not need to be included in the force balance for this specific problem. The user confirmed they obtained the correct answers with assistance from the forum.
StrawHat
Messages
33
Reaction score
0

Homework Statement


BtMla.png

**Hope I don't get in trouble for posting a screenshot of this online homework question...**

Homework Equations


\SigmaFx = marad = \frac{mv^2}{r}
\SigmaFy = mg

The Attempt at a Solution


Simple equations allowed me to find r = 1.323m and θ = 41.41°
\SigmaFx = Tuppersinθ + Tlowersinθ + mgsinθ = \frac{mv^2}{r}
Tuppersinθ + Tlowersinθ + 28.85N = 169.57N
Tupper + Tlower = 212.75N

\SigmaFy = Tuppercosθ - Tlowercosθ - mg = 0
Tuppercosθ - Tlowercosθ = mg
Tupper - Tlower = 58.15N
Tupper = 58.15N + Tlower

Substituting Tupper,
58.15N + Tlower + Tlower = 212.75N
58.15N + 2(Tlower) = 212.75N
Tlower = 77.3N
Tupper = 58.15N + 77.3N = 135.45N
 
Last edited:
Physics news on Phys.org


StrawHat said:
Simple equations allowed me to find r = 1.323m and θ = 41.41°
Good.
\SigmaFx = Tuppersinθ + Tlowersinθ + mgsinθ = \frac{mv^2}{r}
In what direction does the weight act?
 


Doc Al said:
In what direction does the weight act?

Away from the pole, so I guess mgsinθ is negative as well?

EDIT: Ah, nope. Fx is only mv^2/r, so I don't need to take into account the gravitational force. Got the answers, thanks for your help!
 
Last edited:
Thread 'Collision of a bullet on a rod-string system: query'
In this question, I have a question. I am NOT trying to solve it, but it is just a conceptual question. Consider the point on the rod, which connects the string and the rod. My question: just before and after the collision, is ANGULAR momentum CONSERVED about this point? Lets call the point which connects the string and rod as P. Why am I asking this? : it is clear from the scenario that the point of concern, which connects the string and the rod, moves in a circular path due to the string...
Back
Top