Hydraulic Piston Supporting a 500lb weight

Click For Summary
To determine the force vector F necessary to support a 500 lb weight using two hydraulic pistons, the equation F1/A1 = F2/A2 was applied, but the initial calculation for F1 was incorrect as it did not account for the lever mechanics involved. The user attempted to incorporate torque by using the formula Torque = rF, but this also yielded an incorrect result. Clarification was provided that the ratio of forces at the pistons and the hand corresponds to the distances from each to the pivot point. This insight helped to refine the approach to solving the problem. The discussion emphasizes the importance of understanding both hydraulic principles and lever mechanics in such calculations.
AsuraSky
Messages
16
Reaction score
0

Homework Statement



Piston 1 in the figure below has a diameter of 0.31 in.; Piston 2 has a diameter of 1.7 in. In the absence of friction, determine the force vector F necessary to support the 500 lb weight.

p9_24.gif


Homework Equations



F1/A1=F2/A2



The Attempt at a Solution



I used the equation above and found the areas of each piston and solved for F1


F1/.075477=500/2.2698

F1=16.626

That answer was wrong so I thought about it some more and realized that the force I solved for was the force on the piston and not the lever that the question asked for. So I had this crazy idea that since there was sort of a rotational force on the hinge when you push the lever down you can use Torque = rF with torque being the force previously solved for

16.626 = 10(F) (r=10 for the 10 in distance between force F in the diagram and piston 1 in the diagram)

F= 1.6626

This answer was also marked wrong and I have run out of ideas on how to solve this problem. If anyone can point me in the right direction it would be greatly appreciated.
 

Attachments

  • p9_24.gif
    p9_24.gif
    5.3 KB · Views: 720
Physics news on Phys.org
Right method, slight oops.

The ratio of force at the piston and the hand is the ratio of the distances from each of them to the pivot.
 
Thanks, that cleared things up for me.
 
The book claims the answer is that all the magnitudes are the same because "the gravitational force on the penguin is the same". I'm having trouble understanding this. I thought the buoyant force was equal to the weight of the fluid displaced. Weight depends on mass which depends on density. Therefore, due to the differing densities the buoyant force will be different in each case? Is this incorrect?

Similar threads

  • · Replies 2 ·
Replies
2
Views
3K
Replies
6
Views
2K
  • · Replies 3 ·
Replies
3
Views
3K
Replies
1
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 2 ·
Replies
2
Views
8K
  • · Replies 21 ·
Replies
21
Views
8K
  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 1 ·
Replies
1
Views
5K
  • · Replies 7 ·
Replies
7
Views
7K