Balance Definition and 491 Threads

Visualize a simple balance, a pan at either end of a beam which balances on a fulcrum. The way it works is that if each pan carries the same weight, it balances horizontally. If one pan carries slightly more weight, it tips slightly off horizontal. If one pan carries more weight yet, it tips...

Mod note: Moved from technical forum, so missing the HW template. Hello everybody and happy new year :partytime: Here is a solution for the following case. Do you agree with ? Thank you in advance for your answer The question is to give the values of T0 T1 and d in terms of g', L and G in...

Hello, I have a few questions regarding the osculating plane, which I understand to be the plane generated by the Principal unit tangent vector and principal unit normal vector (both are orthogonal), and the inertial Cartesian z-axis. Ultimately, I plan to understand the geometric/kinematic...

so I understand that it balances both sides of the scale but why does it have to be horizontal? in other balancing systems the beams do not have to be horizontal but in this system they do. I know it has to do with torque but can't seem to understand how the balance can be close to the right...

Homework Statement In heat impervious bowl with unknown volume there are unknown amount amount of water(10 degress celcius). Metal ball with unknown mass / volume / specific heat(ball temperature was 100 degress celcius) - was landed in water and managed to raise temperature to 40 degress...

Acetylene (C2H2) is reacted with excess O2 in a container. After complete reaction, the volume of the gaseous mixture of the combustion products is 300ft3 at 60C and 10mmHg gauge pressure. P(atm) is 735mmHg. The relative humidity if the product gas is 100% with no condensed water present...

Homework Statement Balance :- $${Cl_2O_7} + {H_2O_2} {\longrightarrow} {ClO_2^-} +{O_2} + {H^+}$$ Medium :- basicHomework EquationsThe Attempt at a Solution $${\stackrel{+7}{Cl_2}\stackrel{-2}{O_7}} + {\stackrel{-1}{H_2}\stackrel{-1}{O_2}} {\longrightarrow}...

Question: On the Moon, the force of gravity on an object is only about one-sixth of its value on Earth. Decide whether each of the following would give an accurate measurement of the mass if used on the Moon a) A beam balance like the one in the diagram at the top of the page b) A balance...

Hi PF! Suppose we have an incompressible UNSTEADY fluid passing through a level pipe. Let station 1 have area, velocity, and pressure ##A_1##, ##V_1(t)## and ##P_1(t)##. Station 2 is defined similarly. I know the unsteady Bernoulli equation could solve this, but if I wanted to make a momentum...

I spoke with a professor I'm working with about my personal statement for graduate school. She took issue with my beginning paragraph: "My interest in plant science grew out of my desire to create peace between humanity and their environment. Anxiety over doomsday scares of global warming drove...

Homework Statement The diagram shows a rigid conducting wire loop connected to a 6.0 V battery through a 6.0 V, 3.0 W lamp. The circuit is standing on a top-pan balance. A uniform horizontal magnetic field of strength 50 mT acts at right angles to the straight top part of the conducting wire in...

Homework Statement "In Fig. 8-33, a runaway truck with failed brakes is moving downgrade at ##130\frac{km}{h}## just before the driver steers the truck up a friction-less emergency escape ramp with an inclination of ##θ=15°##. The truck's mass is ##1.2⋅10^4kg##. What minimum length L must the...

Homework Statement Given: AD=DC = 9m P=78kN S=25Kn Angle alpha = 35 deg A is static but B is movable I need to solve forces on the bases A and B I do not understand where do I mark the forces if there is a base that can move. Homework EquationsThe Attempt at a Solution My attempt: I am...

Homework Statement Given: a=10m l=18m P=18kN angle alpha = 35 deg The task is to calculate the base reaction forces on A and on B Homework EquationsThe Attempt at a Solution This is my attempt on creating the balance equation system.[/B] When replacing the variables with numbers, and...

Homework Statement [/B] P=60kN angle alpha = 45 degrees angle beta = 20 degrees The task is to calculate the force on the base A and C, and to draw vectors that represent those forces. Homework EquationsThe Attempt at a Solution I did similar examples at the class, but when I had to do this...

Hi, I am currently studying Thermodynamics and stumbled upon this equation and is slightly confused as to how this works. Hopefully someone can help me with the understanding. According to this text here, if I am not wrong e can be h + ke + pe or u + ke + pe depending on where i am looking...

In equation of photosynthesis were see 6 O2 is produced In equation of respiration we see that 6 O2 is used. But if plants produce and take back the same amount of O2 then how is the balance of oxygen in Earth maintained?

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?

Homework Statement A beaker is filled with water and its weight is measured by a balance scale. The reading is recorded as R1. 1. A ping pong ball is now submerged in the water without touching the wall and the bottom of the beaker. What is the reading, R2 of the balance scale? 2. A steel...

I want to build a Self Balancing autonomous bicycle for which I need to know about CMG System,Can Any one please guide me to the basics of Gyroscope and CMG- Ebooks would be a great starts.

Homework Statement I am doing a course called Financial Accounting Fundamentals (BAF3M-B) and I was told that physics forum provides help with qts related to this subject. Anyways, Here is the question I'm having trouble with: Sorry if the scanned version is a bit blurry :P a) Journalize...

Homework Statement Felder & Rousseau 4.73 (p. 184) A mixture of propane and butane is burned with pure oxygen. The combustion products contain 47.4 mole % H2O. After all of the water is removed from the products, the residual gas contains 69.4 mole% CO2 and the balance is O2. What is the mole...

Planck constant in http://pdg.lbl.gov/2015/reviews/rpp2015-rev-phys-constants.pdf determined to 12 ppb. Planck constant in https://www.sciencedaily.com/releases/2016/06/160621115645.htm was measured with 34 ppb and it is a big step forward in replacing of Paris kilogram with more stable...

Greetings, There seems to be a supposition in astronomy that charged black holes are uncommon. Is this assertion well supported? According to a paper I found by Briet and Hobill, if you look at gravitational lensing alone charged black holes look just like regular black holes, but with a mass...

https://en.wikipedia.org/wiki/Balancing_of_rotating_masses See the image in that page. I know intuitively why a direction of torque is counterclockwise-because of a centrifugal force. But an direction of angular momentum of that shaft with attached weights (ignore the shaft mass) is southeast...

I am confused about a topic regarding torque and slippage. I have been led to believe that for a car initially traveling at some constant speed: the torque at the axle of a wheel will be equal to the torque caused by static friction at the point of contact of the wheel. This is true so that the...

Homework Statement A 30 kg wheel has a center of mass 0.1 m left from the center of the wheel and radius of gyration KG = 0.15 m. Find the angular acceleration if the wheel is originally at rest. The radius of the wheel is 0.25m. Homework Equations I=mk^2 T=f*d M=I*a Fn acting bottom in Y...

Homework Statement I am given a tool that needs to be balanced in the horizontal position with a spring of my design. I need to know the force that the spring will need to exert in order to do this. I am also choosing the mount point, which will be at 10 in. Homework Equations Fsy =...

Hi PF! For the longest time I thought an energy balance and the heat equation were identical procedures. However, recently I saw an example of a steady state, constant property, laminar flow of fluid between two flat surfaces where the top surface moves in the ##x## direction at ##V_1## and we...

Essentially I have a spindle with a weight placed at a fixed point. There are four different weights to take into consideration, all are positioned at the same point. The results I have show what the voltage (pk-pk) output there is, therefore I can see how the out of balance varies depending...

I was just scrambling and thought of rockets. So I came up with an equation for (hovering). Note: This might be totally wrong. Okay so we have a rocket with fuel with a mass of M. There is gravity acting on it so I need a force to balance things out. F - Mg = 0 F = Mg What I have learned is...

Hey guys, I'm really stuck right now 1. Homework Statement Habitable exoplanet: Now we will include a convective heat flux (H), with H being proportional to the difference between the atmospheric and ground surface temperature, $$H=c_p(T_a-T_p)$$ with c = 1.2 Wm−2K−1. Calculate the temperature...

Hi all, I'm having some trouble figuring out why entropy is used instead of enthalpy for an open system. From what I understand, an open system uses entropy to calculate internal energy. Since the control volume is constant (i.e. Δv = 0), wouldn't using : h = u + PΔv effectively be h = u? So...

I am a noobie and I am not really sure this is the right forum to post to, so please excuse me if I am posting in the wrong place. I had considered General Physics and Classical Physics, but I hope I have made my best choice and I don't think it is acceptable to post in more than one forum...

I'll be using a mass balance calc for a tank design at work. We are designing a tank that has an automatic float switch on it, attached to a valve which will start filling the tank when the water level drops below a certain point. This tank is intended to drain quickly (flow rate not known at...

Hi everybody, Glad to be with you, in the most popular physics forums on the Internet. First of all, I'm not a physicist and the problem I hope to get the answer from you, is part of the work I'm writing in another field. To cut it short, I don't quite understand how the relativity of...

Homework Statement A light spring passing over a smooth pulley carries a spring balance of mass 1 kg and two weights of masses 1 kg and 2 kg. the reading on the balance will be Homework Equations 3. The Attempt at a Solution [/B] to my knowledge whatever the tension above the spring balance...

Homework Statement I have 4.6 gram of starch and I want to add 30 % of sorbitol to xylan. How much gram of sorbitol, should I weigh on the balance? Homework EquationsThe Attempt at a Solution

Homework Statement Two well-insulated rigid tanks of equal volume, tank A and tank B, are connected via a valve. Tank A is initially empty. Tank B has 2 kg of Argon at 350 K and 5000 kPa. The valve is opened and the Argon fills both tanks. State 2 is the final equilibrium state. The temperature...

Homework Statement What number of electrons to balance the equation ##I_2(s)+OH^-(aq)\rightarrow IO_3^-(aq)+H_2O(l)## The Attempt at a Solution I see that the oxidation state of I increases from 0 to +5 But, I don't see any reduction at the reaction.. So, I don't understand how to balance the...

Homework Statement Describe the relationship between the resulting torque from each scenario using the torque equation. Question this question is addressing- Using the bricks from the materials on the right, create and record 10 different combinations of two unequal masses that result in a...

Homework Statement [/B] A stream of elastic glass beads, each with a mass of 0.53 g, comes out of a horizontal tube at a rate of 99 per second. The beads fall a distance of 0.49 m to a balance pan and bounce back to their original height. How much mass must be placed in the other pan of the...

Homework Statement A string is hung over a fixed pulley, and a mass of m3 is suspended from one end of the string. The other end of the string supports a massless pulley, over which a second string is hung. This string has a m2 mass attached to one end, and a m1 mass attached to the other end...

Homework Statement Perform a one-dimensional energy balance for the heating of a fluid through a hot pipe in order to develop a differential equation that governs the variation of the mean temperature of the fluid along the length pipe. The pipe has an inner diameter D and length L; its walls...

Homework Statement Water, initially saturated vapor at 4 bar, fills a closed, rigid container, The water is heated until its temperature is 400C. For the water, determine the heat transfer in KJ per kg of water . Homework EquationsThe Attempt at a Solution Assume potential and kinetic...

What is the general procedure for calculating the mass of air in mass balance problems? what assumptions must be made? How do i convert this into mass from a percentage, e.g 21% oxygen & 79% nitrogen?

Hello, PF! Recently, while reading chapter 10 (microscopic energy balances) of the second edition of BSL, I found a minor discrepancy which is confusing me, especially when considering the mathematical analogies of heat and mass transfer. In section 10.1, the authors introduce Newton's law of...

Hello, I was reading an article, and I found something unfamiliar(sorry I am not into heat transfer a lot) : For the energy balance of the fluid, I didn't understand the mCpθ where θ is the temperature and mCp(θ+dθ/dx θ) terms. I know that for a control volume, the energy balance for...

Hi, I'm trying to understand the physics on a Scrambler; and am having difficulty with balance of torques equation. In below image a vehicle is moving to the right while breaks are applied. The balance of torque is defined as: h * F1 + h * F2 + b * N1 = (B-b) * N2 I understand the...

Good evening, people of PF. Recently, while studying chemical kinetics, I have come across some questions about reaction rates and rate equations. I've noticed some inconsistencies between the chemical kinetics point of view, and the approach taken by chemical reaction engineering and reactor...