Rotational Statics Of A Balance Beam

  • Thread starter mrshappy0
  • Start date
  • #1
99
0

Homework Statement


A gymnast with mass m1 = 48 kg is on a balance beam that sits on (but is not attached to) two supports. The beam has a mass m2 = 121 kg and length L = 5 m. Each support is 1/3 of the way from each end. Initially the gymnast stands at the left end of the beam.
1)What is the force the left support exerts on the beam?


Homework Equations



F=ma=o
T=Iang.acc=o



The Attempt at a Solution



So I just solved a problem where I solved for the tension in a string holding up a beam attached to a wall...etc. I am not really sure how to transfer the same equations to this situation. So far I know that the net force and net torque on the system is zero. So for example I know that a hinge in the other problem acts a net force of Mass of the beam by the gravity. Not really sure what formula to use for the beams.
 

Answers and Replies

  • #2
PeterO
Homework Helper
2,426
48

Homework Statement


A gymnast with mass m1 = 48 kg is on a balance beam that sits on (but is not attached to) two supports. The beam has a mass m2 = 121 kg and length L = 5 m. Each support is 1/3 of the way from each end. Initially the gymnast stands at the left end of the beam.
1)What is the force the left support exerts on the beam?


Homework Equations



F=ma=o
T=Iang.acc=o



The Attempt at a Solution



So I just solved a problem where I solved for the tension in a string holding up a beam attached to a wall...etc. I am not really sure how to transfer the same equations to this situation. So far I know that the net force and net torque on the system is zero. So for example I know that a hinge in the other problem acts a net force of Mass of the beam by the gravity. Not really sure what formula to use for the beams.
You can indeed use torques, and take them about any point you choose.

All you need is the size of the force, and the distance from its [effective] point of action to your chosen reference point.

Since you don't know the force provided by either support - choosing one of them as you rotational reference is the most logical.
 

Related Threads on Rotational Statics Of A Balance Beam

Replies
2
Views
2K
Replies
3
Views
4K
  • Last Post
Replies
4
Views
8K
  • Last Post
Replies
13
Views
1K
  • Last Post
Replies
2
Views
3K
  • Last Post
Replies
6
Views
7K
  • Last Post
Replies
3
Views
1K
  • Last Post
Replies
6
Views
9K
  • Last Post
Replies
1
Views
2K
  • Last Post
Replies
2
Views
5K
Top