Weight Definition and 1000 Threads

Homework Statement We have an object, whose mass is accumulated in its center. The mass is m. We let an object positioned at the height of h over the scale free fall. Let R be the number that will be displayed on the scale right when the item hits it. Find R(h). 2. The attempt at a solution...

OK I'm not sure if I put this in right subforum. I remember once reading in some science book by Isaac Asimov that the heaviest any flying animal can be is 22 kg, but I read on Wikipedia that Quetzalcoatlus may weighted up to 250 kg. So how come there's such a great difference in that...

Homework Statement Julia plans to make a cylindrical vase in which the bottom of the vase is 0.3 cm thick and the curved, lateral part of the vase is to be 0.2 cm thick. If the vase needs to have a volume of 1 liter, what should its dimensions be to minimize its weight? Homework Equations...

Hey guys, I am building a small water ramp that will extend from a dock and into the water with a buoy at the end. I could probably just use trial and error, but thought it would be fun to make some rough calculations to help my design. This picture (http://imgur.com/a/bHYfG) shows the...

Since 97% of everyday weight scales (both in doctor offices and at home) measure our actual mass either in lbm and/or kg, and NOT force (lbf or N), then why does oxford choose to define weight to be relative? "a body's relative mass or the quantity of matter contained by it, giving rise to a...

Homework Statement Given three spring scale readings, positioned at unknown angles, find the mass of the weight hanging from all three scales without using trig, and without measuring the angles. You have only a yard stick. This is a static equilibrium problem. Homework Equations Not allowed...

Homework Statement Hi everyone,I just want to know if my answers are correct. Homework EquationsThe Attempt at a Solution 1. For each situation, indicate whether the normal force exerted on you will be gater tha,less than or equal to your true weight. a) Elevator starts to move down from the...

Homework Statement Each cord can sustain a maximum tension of 31 lb . Determine the largest weight of the lamp that can be supported. Determine θ of cord DC for equilibrium. Homework EquationsThe Attempt at a Solution I found the answer to the first part of the problem (24.4lb) but not sure...

if i got a beam of 40 meters and one side (35m) is 12 metric ton how do i calculate the forces on the gyroscope. I tried to caclutate it but i just get a torque and a angular momentum, how do i converted torque and angelur momenten in Netwons?

Okay, I just want to confirm...When we take an object to some height, let's say a bag taken upstairs, Do we have to apply the upward force equal to the weight of object or more than the weight of the object...? I know that its more than weight..But just want to confirm...

Suppose there is a beaker filled with water placed on a weighing machine. Suppose the reading is x kg. Now, if i immerse a solid block inside the beaker without touching the walls or the bottom of the beaker, will the reading given by the weighing machine increase or not?

Suppose there is a pulley(of negligible mass) and a string(of negligible mass) passes through the groove and two equal masses are attached to each end of the string. Now, if the whole arrangement is attached on a spring balance what will be the reading of the spring balance. Will it be zero?

In what follows I refer to the ideas of "Thermodynamic: Foundations and Applications" by Gyftoploulos and Beretta. The abbreviated form of my question is: In a reversible weight process, Ω1R-Ω2R = E1 - E2 (see eqn. 6.18, p. 99) is transferred out of the composite of a system A and a reservoir R...

Homework Statement [/B]A man sits on a rotating chair. the moment of inertia of them both is Im. he holds two weights m, each in a spread out hand, and rotates at frequency f1. the distance each mass from the chair's axis is r1. he then pulls his hands closer, each to r2. What's the new f2 and...

Hi, I need to figure out how much weight a 5 foot steel pipe will support before becoming unsafe. I am building a series of out door pull up bars for my neighborhood as an eagle project. I need to buy the right pipe/tube that will be sturdy enough but not have too big of a diameter that you...

Let's say that a man standing on a scale on the surface of the Earth weighs 1000 Newtons. Now let's place the scale at the end of a very long pole extending far from the surface of earth, considering the Earth to be static. Let's say that the man on the scale now weighs 100 Newtons. If we were...

Please show me the relationship that proves how an inclined plane's angle of incline, θ, is equal to the angle used to find the components of gravity force. I know that the angles are the same, but I'd like a way to show it. Thanks!

I have read that the apparent weight of a person in a lift accelerating with acceleration 'a' downwards is given by: W = m(g-a) where 'm' is his mass so if a>g, then one feels negative apparent weight. But, it is also true that one becomes conscious of his weight only when he gets a reaction...

I am 29 with a wife and daughter, scheduled to graduate in 1 year with a B.S in physics. My GPA currently sits at a lowly 2.5, however I have been working full time(40 -52 hours a week) while being a full time student. I mostly have received B's in my core classes (2.79 GPA in major). Do...

This is not strictly a physics question, I just figured this is the best place to ask it. I think everyone is familiar with the subtle difference in the effects of gravity from the poles to the equator. At or near the equator, objects weigh about 0.5% less than they do at or near the poles. My...

Homework Statement See attached picture. Homework Equations Change in work = force x distance moved The Attempt at a Solution So I took the ratio AC/AB = 1/ $\sqrt{2} $ which I set equal to T/50 where T is the tension we want to find. Solving this gave me T=50/ $\sqrt{2} $. I just wanted to...

Hello, new member here so first post, I apologize for any unintentional faux pas. Anyway... I have a problem which I have been asked to sort out in my work place. We have a rig which is used to move a pneumatic ram up and down. Currently it is on an electrical winch system and I have been...

Okay so first of all forgive me if I sound dumb, and forgive my english, is not my primary language. So I know two objects will fall at the same rate if air is excluded, so what I am asumming its that free fall formula is only correct if there's no air, right? So I am a programmer and I want to...

Homework Statement An ##D## meter long wooden stick with a mass of ##M## is placed on two chairs of neglegible lenght. The left is ##L## meters from the left end and the right is ##X## meters from the right end. Find the expression for the both Normal forces that act from the chairs. Homework...

Why do we take the Center of mass to be on the right side rather than on the left? A uniform circular disc of radius 4a with a circular hole of radius 2a made in the disc. The mass of L is m and a particle of mass km is now fixed to L at the point P. The system is now suspended from the point S...

I am having trouble visualizing which two tires of a car will be pushed down based on the angular momentum and torque of that car. Let's say if its angular momentum is point OUT while its torque is pointing UP in relations to the picture below. My guess is it's the two right wheels of the...

In studying physics over many years, I am still perplexed that gases have weight. I understand that gases are composed of molecules, but if they are moving in all directions with much space between each molecule, how is there a downward weight that can be measured with all that space in between...

weight is the force of a body on a surface or on a rope. So why isn't it always perpendiculair to the surface, for example in a slope. When a slope is so steep that it's vertical, there is no weight. But when the slope is a little diagonal you talk about a weight (which faces down(to the center...

Homework Statement A person of weight w is in an upward-moving elevator when the cable suddenly breaks. What is the person's apparent weight immediately after the elevator starts to fall?

Neglecting equatorial bulge and using 'g' (9.81m/s^2) as standard before calculations, I wanted to see if I could calculate the change in 'g' before looking it up. Obviously this not a difficult sort of problem but I am finding myself a tad confused about something. It seemed intuitive to me...

How much does a 12in(height) x 40in(length) x 2in(width) rectangular box weigh?

Homework Statement What is the force needed to accelerate a 2.0kg ball at 3.0ms^-2 a) In a frictionless horizontal surface, near the surface of the Earth b) Vertically upward, near surface of the Earth Homework Equations f=ma w=mg The Attempt at a Solution For a) F=2(3) = 6N By inputing the...

Homework Statement A uniform beam at equilibrium is suspended by a cord at X which is 2m from one end of the beam and and 3m from the other end. There is a mass of 28N attached to the 2m end and a mass of 10N on the 3m end. Determine the weight force of the beam Homework Equations...

Homework Statement A mild steel wire of length 1 m and cross-sectional area 0.5*10^-2 cm^2 is stretched within elastic limit horizontally between two pillars.A mass of 100 g is suspended from mid-point.Depression at mid-point? Homework Equations Sag in metal rod is=WL^3/(4BD^3Y) where...

Homework Statement An astronaut in a rocket has an apparent weight of 1.35x103N [down]. If the acceleration of a rocket is 14.7 m/s2 [up] near Earth's surface, what is the astronaut's true weight? The acceleration due to gravity on Earth's surface is about 9.81 m/s2 [down]. Mass of Earth is...

Hi all, I'm new to the forum so I hope I'm posting this in the right place. I'm currently working on a senior design project which requires my team to create a working prototype of a coaster that changes color based on how full the drink on top of it is. We plan to control the prototype with...

Homework Statement Ned climbs to the peak of Mt. Everest, the tallest peak on Earth at 8850 m above sea level. Ned's mass is 95 kg, the mass of Earth is 5.98 x 1024 kg, and Earth's radius is 6.37 x 106 m. What is the difference in Ned's weight when comparing his weight at the top of the...

I've been bothered about this for a while now. As a volleyball player, I am constantly looking for ways to increase my vertical. So, my question is: Will an increase in muscle mass decrease my vertical? On one hand, I am getting stronger and therefore should be able to push harder off the...

Homework Statement If weight x distance over time equals work done. Work done divided by time will give me work done over time foot pounds. Foot pounds can be converted to horsepower. So I should be able to find minimum horse power needed to push a known weight a known distance in a known time...

I read that if the temperature of 1 Kg of gold rises by 10°C its mass increases by 1.4 * 10^-14 kg. Can you please explain how you get such value from E= mc^2? I think the increase corresponds to E = h f =1.53*10*10^36 and since 1 kg has 1.1*10^30 electrons, each one gets 1.4*10*6 h but 10...

Can someone explain me what is the connetion between centrifugal force and weight force thanks ? In which situation should I use the centrifugal force (that is a fake force) ?

Hey everyone. I've never been very good at math/science so I'm seeking a little help from this forum in hopes that there is someone out there who can provide me or guide me to an answer. What I'm trying to figure out is the difference in force or pressure exerted on the human spine for an...

Homework Statement Problem - A 120-kg mail bag hangs by a vertical rope. A worker then displaces the bag to a position 2.0 m to the side from the original position, always keeping the rope taut. What horizontal force is necessary to hold the bag in the new position ? Note :- We have to use...

In my lectures and notes my professor keeps writing out density as lbs/ft3 and unit weight as lbs/ft3. For a material such as concrete it could have a density of 167 lbs/ft3 but a unit weight of 103 lbs/ft3. I am confused as to how these two values are different even though they have the exact...

Homework Statement Equivalence factor of the salt is FeSO4.Cr2(SO4)3.24H2O is Ans is 8. Homework EquationsThe Attempt at a Solution Equivalence factor of an acid or base is its basicity or acidity, and for a compound undergoing redox reaction, it is the number of electrons exchanged per mole...

Homework Statement is the equation in the 3rd photo wrong ? since there are 2 exits , why shouldn't the eqaution become (P1 / y) + z + (8.33^2) / (2x9.81) = 0 + z +[ 2 (12^2) / (2x9.81) ] ? Homework EquationsThe Attempt at a Solution

Homework Statement A 65-kg woman descends in an elevator that briefly acclerates at 0.20g downward when leaving a floor. She stands on a scale that reads in kg. (a) During this acceleration, what is her weight and what does the scale read? Homework Equations ƩF = maThe Attempt at a Solution I...

Scott Kelly is coming home after a year in space. I try to follow these things and watch the interviews with all the questions, most of which seem straightforward and informative. What drives me nuts, though, is the ubiquitous absence of probably the first question I would ask Scott Kelly or...

Homework Statement why the formula of weight of fluid block is given by the formula of ρg[ (R^2) - pi(R^2) ] 1? what does the 1m mean here ? shouldn't it = ρg (pi) (R^2) h ? 2. Homework Equations The Attempt at a Solution

I'll preface this with saying I'm an Industrial Designer, not an engineer. I also build workshop furniture as a hobby, which this question is in reference to. I'm building a motorcycle lift table. I'm curious, is there a chart that compares things like tubing material, size, strength and...