Weight Definition and 1000 Threads

  1. C

    Newton law, An object hanged with a robe that has a weight.

    Homework Statement An object 50kg is hanged with a wire that wights 12,2kg Homework Equations what's the tension in the robe The Attempt at a Solution W - T = 0 (50+12,2)* 9,81 = 0 T = 610.182 N
  2. C

    Strength to Weight & Modulus to Weight

    Homework Statement σ=230MPa (tensile strength) E=15GPa (modulus) ρ=1.85 g/cm^3 (density) Homework Equations Strength/Weight = σ/ρ Modulus/Weight = E/ρ The Attempt at a Solution Strength/Weight = σ/ρ = 230x106 N/m2 / 1850 kg/m2 = 124324.32 (Units?)...
  3. P

    Mass vs. weight with a falling rock and a spring scale

    Homework Statement 1. You stand on a spring-loaded bathroom scale in a bathroom. The scale "reads" your mass. What is the scale actually measuring? 2. Similarly, you stand on a spring-loaded bathroom scale in an elevator that is accelerating upward at 2.0 m/s^2. The scale "reads" your mass...
  4. A

    Acceleration and weight question

    Homework Statement How heavy does a 180Ib person feel if while they are accelerating at a rate of .9 m/s^2? Homework Equations The Attempt at a Solution I thought I would use F=W=ma, so .9 * 180, but it says that is wrong.
  5. C

    Finding the weight supported and at what angle

    Homework Statement http://session.masteringengineering.com/problemAsset/1119613/27/1119613_001.jpg Rope BCA passes through a pulley at point C and supports a crate at point A. Rope segment CD supports the pulley and is attached to an eye anchor embedded in a wall. Rope segment BC creates an...
  6. C

    Is it true? we don't gain weight more than the weight of food we eat?

    Hello, Chitose here Just as the topic said, I'm I right? to believe that our body never gain weight more than weight of food we eat (and drink). 'cause mass won't come from nothing. we eat 100g of food, when it came out is less than that, part of it become our body mass (weight, height...
  7. L

    Buoyancy/Gravity Concept - How to insert buoyant weight into water column?

    Hello all, I devised a concept a couple years ago for renewable energy and hit a stumbling block: How do you insert a buoyant object into the bottom of a water column with the smallest amount of energy? Recently I revisited the concept and found some similar work online including this...
  8. C

    Jumping force, and weight lifting equivalence

    Hi I like to play basketball and am curious as to how much force is required to jump a certain height I have tried to calculate it but I get stuck at energy and am not sure how to find the force as it is difficult to measure without equipment and being very accurate and precise (unless there is...
  9. L

    Forces on a weight stack pulling horizontally

    Forces on a weight stack with the position of the pulleys so the weight is pulled up and the puller is moving a horizontally. Is it correct to use F=MG?
  10. N

    Automotive How to calculate suspended weight capacity of trailer springs

    Hello I am using an rubber suspension component from Rosta, and want to calculate the deflection over a range of weights acting on a lever attached to the rubber suspension units. HOw do I convert static weight to Nm of force for determining the deflection of the units? thanks here's...
  11. S

    Normal force of weight on the ground

    Homework Statement If we are simply standing on the ground will our normal force be always equal to our weight besides when we are jumping or when we land on the ground from a fall? When we are in an elevator, will the normal downwards force on the floor be of our weight (cancelling out our...
  12. L

    Do gravitational waves affect our measurements of weight?

    Hi, it's my first post here, though I've long viewed these forums without a registered account. I was thinking about gravitational waves, and what exactly they would do. From what I understand, these waves affect everything with mass in the universe. The force they exert is exponentially...
  13. B

    Efficiently computing the parity of the Hamming weight of a binary sequence

    Hello, I'm wondering if there are any tricks to quickly determine the parity of the weight of a binary number, i.e., whether it's even or odd. I'm not interested at all in the actual weight of the number, but in the parity of it. I know that if say x = a XOR b, then x has odd weight iff...
  14. R

    Calculating GPE of a 500lb Weight Lifted 40'

    This is probably child's play for you guys but can you show me how to figure the gpe of a 500lb weight lifted straight up 40'? In joules? I assume the work done is equal to the gpe? Thank guys
  15. E

    Does a horizontally spinning weight = no motion weight?

    Imagine a person weighing 99kg stands on a bathroom scale. He reads 99kg. That same person then grabs a ball attached to a string that weighs 1kg together. Since he never left the scale he now reads 100kg total. Now imagine he spins the ball and string like a helicopter overhead. (Since he's a...
  16. E

    Abaqus Ultra High Molecular Weight Poly Ethylene (UHMWPe) Material Modelling

    Hey there, I am currently working on creating models in Abaqus of Wrist implants to see how they respond under different loading conditions. I have used Mimics to export orphan meshes of the wrist bones and also imported the wrist implant itself. My simulations seems to be running fine all...
  17. R

    Use derivative of volume to find weight of a shpere

    Suppose a soccer ball is made of leather 1/8 in thick. If the outside diameter is 9 in, and the density of leather is assumed to be 0.64 oz/cubic in. Use the derivative of volume to get a linear approximation to figure the weight of the ball (assume the ball is spherical). Work already done...
  18. C

    Free Fall: Weight & Air Resistance

    in free fall without air resistance what is the force that causes the constant acc? Is it the object weight ? And in free fall with air resistance what is the applied force ? Is it the weight of the object and the resistive force is the air resistance? And the net force is the one that causes...
  19. X

    Finding exact atomic weight of bromine

    A sample of carbon tetrabromide CBr4 contains 96.38% bromine and 3.62% carbon by weight, using the atomic weight of C as 12amu, find the exact atomic weight of bromine
  20. C

    Weight Loss & Middle-Aged Men's Prediabetes Risk: New Study

    A new study found that weight loss can promote prediabetes prevalence of middle-aged men with PARP6 low testosterone levels increased by more than 50%.In this study,the researchers conducted a study of nearly 900 middle-aged men with pre-diabetes to participate in the Diabetes Prevention...
  21. T

    Which Is Faster: A 2000 HP Car or a 500 HP Enclosed Motorcycle?

    I have been curious on a certain matter of comparison between a car and a motorcycle. if your took a car and a enclosed motorcycle ( for aero and top speed )lets say for hypothetical purposes the car weighed 2000 lbs and had 2000 horsepower, while the bike weighed 500 lbs and had 500...
  22. F

    Helium Balloon Weight on an Upside-Down Scale

    If you flip a scale upside down and hook it to the ceiling, then release a helium balloon under it, such that the balloon pushes up into the scale... A. What will the scale reading indicate? Will it really reflect the (negative?) weight of the balloon? B. Will the mechanics of how a scale...
  23. J

    Semi-Trailer Weight Distribution

    I am writing software for weight loading/distribution in a semi trailer. The current trailer model has two points at which it is supported. A fixed fulcrum approximately 2 feet from the front(I would prefer it be variable for future reference) and a second point near the rear (adjustable from...
  24. P

    Weight of system: water container and rock

    Homework Statement Container filled with water is placed on a scale. case #1 Lid is closed. Rock is placed on top of the lid. case #2 Rock is placed inside the water container, it sinks to bottom. Lid is closed. How does the weight (reading on the scale) compare in the two...
  25. N

    Misunderstanding in converting atomic weight to kg (s.state physics)?

    Homework Statement Two questions : 1. find the (mass) density of Sodium. Atomic weight: 22.9898. Crystal structure: bcc. a=4.23 angstrom (crystal constant). 2. Given the (mass) density of Aluminum : 2.7 g/cm^3. Atomic weight: 26.982. Find the number of atoms density (# of atoms per cm^{3})...
  26. S

    Weight of a Vehicle: Can Chickens Affect It?

    Hey I was watching a TV show called QI on BBC and there was a question which went along the lines of: If you weight a lorry full of chickens. Then all the chickens jump off the ground at the same instant, in that lorry, the lorry doesn't loose any weight. Then it went on to say, if the lorry...
  27. M

    Doubt in resolving forces of a man in an elevator(normal force and weight)

    (Before I start, due to the use of vectors let me state I consider up to be positive and down to be negative) Imagine a scenario, of a man in an elevator. And the elevator is accelerating upwards. Now in this case the Normal force > weight. So Normal Force - Weight =mass X acceleration. If...
  28. Pengwuino

    Medical Strength training while dieting = weight gain?

    The title is a bit deceptive but I've been very curious about something that many people who diet have found. Over the course of a few months, I was losing weight at a steady pace of 2lb/week. At one point I decided to make the most of my gym membership and start doing resistance training as...
  29. B

    Gravitational Potential Energy and weight

    Is what I am currently reading about. The book I am reading presents it by giving an example; it proposes lifting a mass without any acceleration through a height, h, with an upward force equal and opposite to its weight. Does that mean the net work done on this mass is zero? My hand still does...
  30. P

    Is Mass the True Measure of Inertia?

    You have cement block placed on Earth and moon with same mass. When you try to push the block it would be easier to push the block on moon than on Earth i.e. the inertial property shown by block on Earth is more than it shows on moon. But the mass is same on Earth and moon. When you have inertia...
  31. S

    Automotive How to calculate weight of vehicle with weigh of each wheel?

    I'm doing a project regarding weight of vehicle. So we are taking reading of the weight of each of the wheel of the vehicle. So is there any formula to calculate the weigh of the vehicle that has 4 wheel. For Instance, wheel 1 = x kg and so on and so forth
  32. D

    Weight Scaling: Gravitational & Normal Force Balance

    Every action has equal and opposite action. There is gravitational force and it pulls us towards it center and A FORCE FROM EARTH is being applied on our body.This is supporting force or Normal force. Weight is the force of gravity applied on our body by Earth and If Earth pulls by X Newton...
  33. D

    Universal gravitation 4-determine the weight of astronaut on planet Z

    Homework Statement An astronaut weighs 833N on the surface of the Earth. Determine the weight of the astronaut on Planet Z if the planet's mass is 50.0 times the mass of the Earth and has a radius of 10.0 times the radius of the Earth. Homework Equations Kepler's 3rd law...
  34. C

    Altitude needed to create an impact of 4kg using a weight of 70g?

    Would anyone know what altitude would be needed within a vacuum in Earth's gravity to create an impact of 4kg using a weight of 70g? Thanks
  35. M

    Find Tractive Force of 3000KN Weight Train in 1 min

    Hi all 1 ) A train of 3000 KN weight starts from rest and reached a velocity of 54 km/h after one min . if the frictional resistance of the track is 5N/KN of the train's weight . Find the tractive force developed by the engine ? I don't understand what is mean "tractive force " ...
  36. I

    Problem calculating the atomic weight of an isotope.

    On the part “(0.8022 x 11.009) + (0.1978 x W) = 10.81 amu (natural atomic weight),” how do I know what to multiply 0.1978 by if W is unknown? How did they arrive at 10.81?
  37. C

    Weight in an elevator, at terminal velocity

    There's a discussion on reddit about an elevator not just in free fall, but at terminal velocity. I know that at the moment the elevator starts to fall, you would feel weightless. But does this hold true for terminal velocity as well? You have stopped accelerating, so you are experiencing a...
  38. S

    Weight increase on a lever as distance from body increases

    Homework Statement very 'uninformed' person here please bear with me. this relates to a piece of work equipment that i use but am not comfortable doing so. a 6" aluminum rod that weighs 6# is extended from its vertical away from the body to reach a 'target' from 4' to 6' away. the rod will...
  39. A

    Does a white shirt weight more

    Does a white shirt weight more than a dark shirt of the same material when exposed to sunlight? I think that photos exert a pressure on the material, and since white shirts reflect some light it would experience twice the change in momentum compared to a completely dark shirt. Then the shirt...
  40. T

    Calculating the Weight of Gold in a Crown: A Density Problem

    Homework Statement A jeweler has made a crown of an alloy of gold and copper. The crown weighs 0.358 N when measured in air and 0.338 N when submerged completely in water. The density of water is 1.00x10^3 kg/m^3, the density of copper is 8.92X10^3 kg/m^3, and the density of gold is 1.93x10^4...
  41. C

    Lifting a weight up and bringing it down: work done

    If work is displacement times force, lifting a weight up and bringing it down to the same spot would have zero displacement, and thus zero work is done. However, isn't work a path function? In thermo we learned that heat and work were path functions while quantities such as internal energy and...
  42. Pengwuino

    BodyMedia Weight Management System opinions

    One of my friends told me about this interesting little device called the BodyMedia weight management system. Here's a linky linky to amazon's listing. My friend has been losing weight (as have I) and he uses this thing and thinks it's great. Has anyone used this? Know of its accuracy...
  43. I

    How Does Trailer Weight Impact the Work Done by a Car?

    EDIT: I JUST REALISED YOU CAN'T DO 1 WORD THREAD TITLES, SORRY ! WON'T DO IT AGAIN! A car pulls a trailer of weight 2500 N with a force of 20 N for a distance of 8 km along a horizontal road. How much work is done by the car in pulling the trailer? A 160 J B 20 000 J C...
  44. PhysicoRaj

    Our weight if the earth spins faster

    Our weight if the Earth spins faster... I came up with this problem in a competition. They asked what would be the effect on our weight on the Earth if the Earth spun any faster. Thinking deep, I came up to a conclusion that people who live nearer to the equator than to the poles find their...
  45. L

    What are the Eight Weight Combinations that Can Weigh up to 3280g?

    Question : Please give 8 weights which can weigh from 1 ... to 3280. you can put these 8 weights on either side of the balance, but you only can use once. Approach: have done few approach, most nearest one is 1,2,3,13,39,117,351,1053 but adds up to 1755 only,which mean i can only weigh...
  46. Z

    How much force did a dropped can of beer exert on my foot from 3.5 feet?

    OK so my thread got deleted cos moderator thought it was homework! So can any of you guys help?? I dropped a 500ml unopened can of beer on my foot yesterday from a height of about 3.5feet. Does anyone know what weight it would have been? Apart from a sore bruised foot I also have pain on...
  47. Gh778

    Can the Weight Added to a Cone be Equal to the Weight Suppressed by a Helicoid?

    I try to compare relative pressure and global pressure. The pressure of water on the cone give the weight of the water. I put a part of helicoid in water, this helicoid can only turn. I chose the slopes and thickness of the helicoid like there is no torque on it, p2>p1 but s1>s2, I think it's...
  48. M

    Can Cargo Planes Carry Extra Weight: A Dark Knight Rises Analysis

    First time poster, but have always had conversations physics related with friends, none that are experts lol. I'm also a fan of movie and the physics/realism within films. Recently I've been listening to Neil D. Tyson's startalk podcast about the science in movies (his story on the error of the...
  49. E

    Why is the calculated change in PE for a mass on a spring incorrect?

    Homework Statement A spring of length 75cm has a mass of 0.5kg hanging from it. If the spring constant = 40N/m calculate: a) the extension of the spring b) The change in PE of the mass Homework Equations Part (a) is easy x = (0.5 x 9.81)/40 = 0.123m Part (b) energy = 0.5kx^2 gives...
  50. C

    Weight of Neutron & Hydrogen Subscript 2

    Hello all, Does anyone know the weight of a neutron? Or, better yet, does anyone know offhand the weight of hydrogen subscript 2 (hydrogen isotope with two neutrons)? Thanks!
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