Help Needed: Solving Two Tough Physics Problems

AI Thread Summary
To determine the force exerted by the bodybuilder lifting a 35-kg barbell underwater, one must consider the buoyant force acting on the barbell, which reduces the effective weight in water. For the hydraulic press problem, the force applied to the trash can be calculated using the ratio of the areas of the pistons, based on Pascal's principle. The input force of 300 N and the radii of the pistons are essential for finding the output force. Understanding concepts such as buoyancy and hydraulic systems is crucial for solving these problems effectively. Clarifying these principles will lead to accurate solutions for the worksheet.
jkd989
Messages
6
Reaction score
0
A bodybuilder is holding a 35-kg steel barbell above her head. How much force would she have to exert if the barbell were lifted underwater?

In the hydraulic press used in a trash compactor, the radii of the input piston and the output plunger are 6.1 10-3 m and 4.5 10-2, respectively. If the height difference between the input piston and the output plunger can be neglected, what force is applied to the trash when the input force is 300 N?

Please answer these questions for me, they are the last two problems on my 100 problem worksheet that is due tomorrow. I have literally spent the past two hours trying to find the answers for these and i really need a good grade...Thanks in advance!
 
Physics news on Phys.org
We don't just give answers here. Tell us how you have started these problems. (hint: do you understand the concepts of buoyancy and levers?)

[multi-post...locking]
 

Thread 'Errors and significant figures'

I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
View full post »
Thread 'A cylinder connected to a hanging mass'

Thread 'A cylinder connected to a hanging mass'

Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
View full post »

Similar threads

Calculating Forces on Steel Barbell & Trash Compactor - Pressure Questions
Replies
5
Views
3K
Calculating Force in a Hydraulic Press
Replies
6
Views
4K
Are the 2nd and 3rd problems in this video correctly solved? (charged dipole and organ pipe problems)
Replies
3
Views
971
How to Solve Tension Problems in Physics?
Replies
32
Views
8K
Help Solve Hydraulic Problem Involving Spring and Rock
Replies
2
Views
7K
Solving Slingshot Problem Homework
Replies
5
Views
3K
Sensors and transducers, transmission, signal conditioning
Replies
5
Views
2K
Fluids - I wish the answer would flow to me
Replies
7
Views
7K
What is the net electric field at point P in this physics problem?
Replies
3
Views
2K
Solving Two Physics Problems: Weighing Rocks and Steel Barbells
Replies
3
Views
4K

Hot Threads

Recent Insights

Back
Top