Weight Definition and 1000 Threads

Homework Statement If a radioactive sample of 59Fe (t1/2= 44.496 d) has an activity of 1000 disintegrations per minute, what weight of 59Fe is present? Homework Equations

Hello, I am trying to calculate the equivalent amount of weight that a submarine would be under at 1000m below the sea. Apologies if this isn't that well explained! At 1000m - 101 atmospheres - which is 14.5 psi per atmosphere - so at 1000m it would be 1464.5 psi. Do I then multiple 1464.5 by...

Homework Statement A weight W is supported by bar AO and cables AB, AC, and AD. Point A lies in the xy plane, if the bar and cables have the strengths listed below, determine the largest value W may have. Hint given: A FBD of joint A is recommendedto being this problem. Bar AO should be...

Sorry if this is a dumb question. How much of an impact does weight have on reentry? I know it's extremely important on lift off due to fuel costs but is it any different on reentry? Are there certain trajectories calculated for different weights?

Homework Statement Suppose I've got a static mass on a downward plane. (For instance a car on a drive way). How would you set up this free body diagram? Homework Equations F = f1+f2...etc The Attempt at a Solution My preference is A, but I've seen it displayed in examples in my book as B...

Homework Statement Answer true, false, or Cannot tell to teach of the five statements below. A) A 2 kg ball and a 3 kg ball are dropped from a tower. The net forces on each other are the same. B) An astronaut stands on a bathroom scale on the surface of the moon; the scale reads the astronaut's...

Hello Guys, This is my first time posting here - just wondering if anyone has some insight on a project that I am working on. I want to be able to temperature control an insulated shoe box sized volume at ~5 degrees Celsius for about 20 minutes. The main constraints are that I would need the...

Homework Statement The cords ABC and BD can each support a maximum load of 100 lb. Determine the weight of the crate, and the angle θ for equilibrium. Homework Equations ∑F= 0 ∑Fx=0 ΣFy=0 Setting derivative of an expression to zero To find critical point Second derivative test for determining...

If I'm traveling on a spaceship at a constant velocity (say 10000 m/s) towards Mars will I feel weightless, or will I feel nearly weightless because I will still be slightly affected by gravity? I know that when astronauts are in the ISS they feel weightless because they are in a constant...

Hi, I need some advice on what steel tubing to go for. I have either 65x35x2mm or 50x25x2mm. The steel tube is 2.4M & stays in upright/vertical position, with an extended 40cm long piece horizontal on top holding some weight between 30-40KG for some time. I would like to go the 50x25x2mm as...

Homework Statement Suppose an object were sent far out in space away from galaxies, stars, or other bodies. How would its weight change? Homework Equations w=mg where w and g are vectors The Attempt at a Solution Since mass is an intrinsic property and doesn't depend on external sources, then...

Imagine a person holding a stick horizontally, the stick is in the shape of a cylinder, with radius(r), length(L), and density(rho), consider the contacting area between the hand and the stick to be a point at the centre of the circular surface pointing toward the person, what is the torque...

I was just reading about Archimedes principle. Suppose a cylindrical body (attached figure) is immersed in liquid of density d. if the weight of body outside liquid is Fout then can we say that this body will immerse in liquid when released to a depth where upward force F2 = Fout. And then it...

This article in Wired http://www.wired.com/2015/08/used-physics-calculate-much-yoda-weighs/ describes a calculation of Yoda's weight from a still from The Empire Strikes Back. The author, Rhett Allain, is an Associate Professor of Physics at Southeastern Louisiana University. I didn't go...

Homework Statement Homework Equations Concept of couple? The Attempt at a Solution First, I calculated the couple about disc, though I'm not sure if I can use this approach. Since 900 N is pulling the string of pulley downwards, I take the couple about disc as 900 x 0.4, which gives me 360...

Homework Statement I have a an arm with an attached hinge and weight that is rotating inside of a circle, but important the arm is not rotating about the center of the circle. The arm is spinning fast enough so that the weight is always making contact with the edge of the circle. I need to...

I am making a science fair project, I need to know how much power a general weight censor needs, google doesn't seem to be helping. And when a weight censor starts consuming energy?? when a certain weight is applied on it and it switches a circuit on, or as long as the weight censor remains...

Are the following definitions of weight valid; The force of gravity pulling on a mass? The force between two bodies due to the force of gravity? Q. Does weight only apply to the force due to gravity on a body in relation to a planet (or satellite, asteroid etc), eg, a man standing on Earth or...

Homework Statement From what I have seen on internet sources, the average force exerted by an falling object on the ground is equal to the work done by the ground to stop the object. Assume collusion is completely inelastic and object sticks to ground after impact. F: Net force on ground m...

Hi, I need to create an electromagnet that can lift a 1 KG Iron block that is kept at 30 cm away from the electromagnet. I have a DC power supply(RXN 305 D) that can provide a voltage of 0-30 Volt and current of 0-5 A. I need to limit the current used to maximum of 3 Ampere. Please help to...

I am looking for a short pedagogical introduction to Young-tableaux and weight diagrams and the relationship between them, which contains many detailled and worked out examples of how these methods are applied in physics, such as in the context of the standard model and beyond for example. I am...

Consider that Earth was placed freely in space, away from the sun. Then another, but similar Earth is brought carefully in contact with it, so that the two planets get locked in place by their mutual gravity fields. Now, would the Earth's suffer a structural collapse, or would they remain more...

I am designing a circuit, in this simple circuit, when a weight isn't applied, the switch will go off and the circuit won't work until a certain weight is applied, how can i design it?? i am totally new and doing this for a science club, i have never designed any circuits with censor. so please...

Let us suppose a rod is inclined on the ground such that its middle point is supported by a peg. It is a uniform rod and the point where it touches the ground is A, mid-point (also the centre of gravity) is C. The rod is inclined at angle theta with horizon. So, we can divide the components of...

hopeing some one can help me...180ft x 40 ft x 2 inches of water ...what is weight of water on roof thanks to all who ponder this as i am sadly in need of help...should have stayed in school lol thanks again people...xerxies

Hi guys, I have a table with vertical peak acceleration values [g] and I want to find out a formula that convert the [g] values into ground reaction forces in units of body weight (BW). I think Newton´s 2nd law (F = m x a) may help but I am stuck on finding a generic relationship (problem is...

I will have 1 week to study for general GRE. I hear it has very little impact on admission. Is this true? Is that enough?

Finding the landspeed a object needs correlating with its area and weight in volume that a object needs to stay above water looking for the equation and plug in methods

hi, This is probably very simple issue, but i am not an engineer nor have an understanding of basic physic... I need to calculate if the tape used to connect (sealed) to ends of the cardboard box will withstand the weight of the product i put inside it. I have a tape properties (tensile strength...

Good day (or night). I am new here, so I hope my question doesn't bother many. If (forgetting other laws of nature) a shoebox where to hit the sound barrier and an F-35 were to do the same. Would the sound waves be equal. Would it sound the same to a ground observer? I always assume that mass...

I have a question. Suppose a man is lifting a Mass. The mass of course pushes it down. Now what is the force the mass is applying to hand of man is it Weight or Force of gravity because weight acts on mass itself. Then what we call it precisely?

Homework Statement An 80.0 kg man is standing on a scale calibrated in Newtons inside an elevator. Determine the apparent weight of the man as shown by the scale as the elevator is a. stationary. [ans.785 N] b. accelerating downwards at a rate of 1.10 m/s^2. [ans. 697 N] c. accelerating...

I did a simple experiment. I took a small block of copper (40g) and sensitive scales. First I cooled the block in a freezer (-2C) and checked its weight. Then heated it up to 300C in the oven and checked weight again. The difference in weight is well observed (4 - 5mg). Results are consistent...

Hi All, If I have a tank 1meter dia 5metres height and a tank 200mm dia (1/5 size ) 5metres high and I have a horizontal tap at the bottom of each. when I open the taps will I get more distance of water from the bigger tank.

Hi all,I would like to know how to calculate the force required to lift a flap (or drawbridge if you proffer) of known weight that is on a pivot and where the pull chain (let’s say it’s a chain) connects to the flap at a known distance from the pivot.I’d also like to be able to calculate the...

Homework Statement So I have a problem/question were tanks are filled with water and its specific weight is 9.45 kN/m^3. They also give you a range of volumes of different tanks. The problem then asks for the plot of added weight (kN) due to the liquid for the given range of the different tank...

So I have a problem/question were tanks are filled with water and its specific weight is 9.45 kN/m^3. They also give you a range of volumes of different tanks. The problem then asks for the added weight (kN) due to the liquid for the given range of the different tank sizes (diameter). My...

Hello everyone, this is my first time here and I was wondering if you could help. I would like to know if there is a way of calculating how much weight this simple component could hold. It will be made from mild steel. TIA Scott

we know that air pressure on our Earth is 1 atm. Also 1 atm = 10^5 P Also we know Pressure(P) equation = P = F/A So, F = P*A So if small area(A) in which we are standing is also taken then pressure force is that area(A) times 10^5(Atmospheric pressure in Pascal) i.e 10^5*A So why don't we...

Hello, I am trying to determine the tension in a belt conveyor transporting material to calculate the motor power required and also tensioning force needed on it. I wanted to know how the material weight that is being carried affects it. I considered the tension to be equal to the friction...

I know there may be different types of cork, but let's take the "average" cork used for cork board, at say, 0.24gm/cm^3. Let's say you make a boat out of that cork. I understand that the weight of water displaced should be greater than the object's total weight (e.g. density of cork less than...

I saw a thread previously created but locked, and I do understand many events like the tug of war, and wrestling have a huge bias to weight. 100kg guy vs 70kg guy. The 100kg guy only needs to push around 70kg and visa versa. I do understand the 70kg guy could be stronger, but generally speaking...

I've been looking up how weight transfers between car tires in various forms of acceleration, and I've found some formulas. For linear acceleration, I found this formula on Wikipedia: ΔWeight = (accel) * (height of center of mass) * (mass) / (wheelbase) en.wikipedia.org/wiki/Weight_transfer...

Weight is defines as the force exerted by the ground on you. F=ma, and m and a are constant. But the weighing machine does not show the same value when you simply stand on it and when you jump on it. So basically my question is, even though force exerted is same, why is there a difference in...

I am trying to design the housing for an electrical core so that it remains buoyant on the surface but can be neutrally buoyant at desired depths through ballast tanks. I am trying to figure out what the core and housing may typically weigh through specifications online of ones already made...

People jog, thereby expending energy, and lose weight because of it. As modern people who understand mass energy equivalence, we know (or can presume) that during the process of running, the body derives its kinetic energy by breaking down ATP in the cells. When this breakdown occurs, the total...

Has any experiment detected the weight of energy, ##1/c^2 \approx 10^{-17}## kilograms/Joule? Wikipedia claims that superconducting gravimeters can measure changes in gravitational force of one part in ##10^{12}##. Wikipedia's table of energy densities says some batteries store of order 0.5...

Homework Statement On Mars, a martian tells you he has 35.0kg of mass. What is his weight on mars? Mars Info: Mass= 6.42x10^23 Radius= 3.40x10^6 Radius of Orbit about sun= 2.30x10^11 Homework Equations FG=GM1M2/R^2 The Attempt at a Solution I tried using the equation above, but i got...

So I know that weight correlates with friction, as in more weight of an object means that it will experience more friction. However, what is not clear to me is why this occurs on a molecular level. Thanks for the help

Hello, I am trying to build a personal (one-manned) propulsion system that will allow individuals to fly above the trees, preferably fast, and for long amounts of time. I plan to do so using propellers. The power will need to be plentiful and long lasting. These are some options that I am...