Weight Definition and 1000 Threads

Increase in weight if an object is illuminated Are there experiments which show that the weight of a body, with initial mass between 1 g and 1 kg, really increases if illuminated for a certain time? Photons have energy E = hf but no mass. If the weight of a body gets bigger after being...

Air rises in water at about one foot per second of time. If a container of air has a lifting force of 100 Lbs and rises at one foot per second what happens when a 10 lb weight is attached to it? What is its speed in the water then? What about 50 Lbs? or 90 Lbs? What is the speed reduction to...

Hi..all. I have replaced a connecting rod against a failed one (in a 10 piston Benz engine) which is 100 GM lesser than original one since the supplier has modified to Euro norms and old rod no more availble. Now after woking 100 odd hours, the engine failed. After dismantling the engine it was...

Homework Statement To simulate gravity, a circular space station with a radius of 150 m is rotated so that astronauts standing on the inner surface move at 30 m/s. If the 75 kg astronaut stands on a bathroom scale what reading will it give? (assume the scale is calibrated in Newtons)...

Homework Statement Suppose the vertical loop has a radius of 6.81 m. What is the apparent weight (Wap) of a rider on the roller coaster at the bottom of the loop? (Assume that friction between roller coaster and rails can be neglected. Give your answer in terms of m and g.) R = 6.81 m...

Hi, I am looking for a 115 VAC motor (able to be plugged into an ordinary power outlet) that is capable of raising and lowering a load of up to 150 lbs. (attached to a cable and a pulley) at the speed of 6 inches per second. I want the speed to remain constant even if the load changes. How can I...

Homework Statement A glass ball of radius 2 cm sits at the bottom of a container of milk that has a density of 1.03 g/cm^3. THe normal force on the ball from the container's lower surface has a magnitude of 9.48 * 10^-2 N. What is the mass of the ball? Homework Equations Normal force +...

Is there a difference between percent weight and percent number? I am working with particle size and I am really confused because I would expect that they would be the same? eg. WEIGHT----Number of particles 5---3 2---1 8---1 % weight of 3 would be 3*5/(5*3+2*1+8*1) = 60%? % number of...

It may superficially sound like a stupid question with a simple answer, but let me explain in more depth. Calories are units of energy, as you probably know, and grams are the the weight of the food. So calories are not directly related to the weight of a food. Foods range in the amount of...

Homework Statement A uniform 165 N bar is supported horizontally by two identical wires A and B. A small 185 N cube of lead is placed 3/4 of the way from A to B. The wires are each o.75 m long and have a mass of 5.50 g. If both of them are simultaneously plucked at the center, what is the...

1. Suppose Earth is a perfect sphere of radius 6,370km. If a person weighs exactly 600N at the north pole, how much will the person weigh at the equator? Givens: r = 6,370km = 6,370,000m Weight at north pole = mg = 600N Homework Equations ω_{av} = θ/t ƩF_{net} = ma a_{c} =...

Homework Statement Homework Equations I_solidcylinder = .5mr^2 I_thinring = mr^2 torque = I*Ω (where Ω = angular acceleration) change in theta = .5(Ω)(time^2) The Attempt at a Solution Attempted to solve for angular acceleration: (2.5)(9.8)(0.1) = (3*0.25^2 + 0.5*4*0.1^2)Ω...

[b]1. A 0.0097561 g quantity of an unknown gas occupies 0.2 L at 500 K and 2 atm. What is the Molecular Weight (MW) of the gas ? [b]2. PV = nRT [b]3. mw=0.0097561*0.082*500/2*0.2 mw=1

Homework Statement A non-uniform is 3.8-m long and has a weight of 560.-n. The bar is balanced in a horizontal position when it is supported at its geometric center and a 340.-n is suspended 0.70-m from the bar's light end. Sketch this system and find the bar's center of gravity...

Homework Statement A steel bar of rectangular cross-section, with height a and width b (into the paper), is placed on a block of ice with its ends extending a little beyond the ice, (ice has a length c). A weight of mass m is hung from each end of the bar. The entire system is at 0 degrees...

What force is necessary to just barely submerge (push Mary under fresh water) Mary if her average specific gravity is 0.95 after taking a deep breath and her weight in air is 660 N? F=mg ; Force of buoyancy=ρgV; F=mg 660/9.8=mass of air mass of air=67.3 force of buoyancy= 67.3 x...

Pascal’s Law states “pressure exerted anywhere in a confined incompressible fluid is transmitted equally in all directions throughout the fluid such that the pressure ratio (initial difference) remains the same”. My question is, are the two scenarios that I have outlined the same? (see...

Homework Statement The total weight o a gas filled balloon is 1500N.THE BALLOON RAISES AT CONSTANT SPEED OF 10m/s.Calculate the resultant force acting on the balloon? Homework Equations The Attempt at a Solution

Hello I would like to know how to calculate the rated capacity of a forklift at different height? How can weight to be carried change as teh height increase...

If object A is more heavier and durable than object B, and both objects are traveling at the exact same speeds, which one would generate more force? I know it sound like a silly question, but I've learned that momentum equals impact force. So I was wondering if the extra weight and durability...

I've learned Kg to Kgf this time I got another question.. I think it's another way around.. "The weight of an object is 25kgf. What is it's mass if local gravity is 9.6m/s^2" Tried this.. 25/(9.6)(9.8)= 25.5kg

Homework Statement Given: 5x10^21 Phosphorous atoms/m^3 in solid solution in silicon Find: atomic percent and weight percent of Phosphorous atoms The Attempt at a Solution I know how to solve for at. % and wt. % when given two values, I am not sure how to get the second value given the...

Homework Statement A roller-coaster car starts from rest at a high point 2 times as high as the top of the loop-the-loop. When it is just about to enter the loop from the bottom, a 100 lb bag of bricks fall on the car, causing it to lose 25% of its speed. Neglecting friction, do you think the...

Homework Statement The mass of one planet in a distant galaxy is 0.58 that of the Earth's mass , and its radius is 0.57 that of the Earth's radius. What is Fnew, the factor by which the man's weight is reduced if he were orbiting the planet at a distance of 3.5 Earth radii above the...

Homework Statement Hi all, First post so please go easy :smile: I am designing a Dumbbell support that presents the Dumbbell to the user in the correct exercise starting position (1. Shown on the image.) . The problem I am facing is the counter balance to the support. The Dumbbells range from...

I looking to make my own changing table to travel with. Want hard plastic material, non toxic that can hold baby weight. Any ideas?

[b]1. Hi all. Can anyone please help me find the torque required for rotating a shaft which has two masses 1000 Kg each at 120 Degree angles. Please refer to the attachment for clarity. Homework Equations The Attempt at a Solution

Homework Statement The Pilot of an airplane executes a loop-the-loop manuever in a vertical circle. The airplane's speed is 300 mi/h at the top of the loop and 450 mi/h at the bottom. The radius of the circle is 1200 ft. Use American Engineering units in this problem. A) The pilot's...

Homework Statement How would the weight of a person in some place (48 North and 123 West) change if the rotation rate increased so a day was 3 hours long? Homework Equations F=ma The Attempt at a Solution The above is not the only equation I think that is needed for this. Not...

Homework Statement Click on photo to enlarge The weight at the end of the rope is 1000 N. Find tensions in T1, T2, and T3. Homework Equations Law of Cosine: a^2+b^2-2ab(cosC)=c^2 SOH-CAH-TOA The Attempt at a Solution T1 has to be 1000N. I figured T2 and T3 have to add up to...

A bottle of coke was taken out of refrigerator. It was then kept in a sensitive weighing balance.Its cap was opened. The initial weight was found to be 2.403 kg. After a while its weight increased to 2.423 kg. Then again it started decreasing. I repeated this experiment for many times. And the...

Homework Statement A scientist assembled large amount of cable. The longest piece of cable that is hung vertically and does not break under its own weight is of length k. He then places another piece of the cable on a friction-less table. A small part of the cable is hanging over one side and...

Homework Statement A weighs 600 N on an elevator when it is stationary. Each elevator accelerates according to the specified arrow that is drawn next to it. In all cases where the elevator is moving, it is moving downward. Find net force, if the elevator is accelerating 2.0 m/s/s upward, even...

Water is poured to same level in vessels having different shapes. If pressure is the same at the bottom of each vessel, the force experienced by base of each vessel is same. Why then do these different shape vessels have different readings when placed on weighing scale?

Hey guys, first post here... So, I'm having an issue comprehending this topic: Let's say you have a box which weighs 3 N, and you place a 7 kg block on top of it. So, since the block is laying on a horizontal plane, the weight is mg, or 6*10=60 N. Total weight=60+3=63 Let's say you have an...

Homework Statement Find a 68kg person's weight on top of Mt. Everest (8848m above sea level) Homework Equations The Attempt at a Solution

Homework Statement Suppose the length of your forearm is 34cm and its mass is 1.3kg. If your bicep inserts into the forearm 3.5cm from the pivot (the elbow), and your biceps muscle can produce a force of 800 N, how much weight can you curl? Model your forearm as a uniform rod. I have no...

Homework Statement What is the force done by the spring if an object of mass m is attached. Homework Equations F=ma F=-kx Fg=mg The Attempt at a Solution Sum F = 0 mg-kx=0 mg-Fs=0 Fs=mg Therefore the force done by the spring is mg? is the +/- right? for direction? Is the...

Thrust and Mass verses g force upon object Have designed a solid fuel and liqiud fueled rocket engine. Not great in mathmatics! Have total weight of fuel engine and power supply at 2.3 pounds Have an engine that burns for 3.3 seconds and produces 47 pounds thrust for 2.1 seconds. If I...

Homework Statement Well, that's all, my mid-term exam came a question that asked me: if a body with mass of 50 kg was weighed on a scale that is inside an elevator in free fall, how much will it weight? I supposed that the same it would weight on the surface, since gravity never stops...

Assume all dims in millimeters and kilos and I am working on a hydraulic set up I have a cylinder Ø200mm diameter x 400 high, it has a hole in the middle Ø10mm going into a capped Ø10mm pipe. The cylinder is filled with water up to 300mm high. There is a bouyant weight that floats on top of the...

Homework Statement In a lab I collected data for change in apparent weight of a ~1kg mass during an elevator ride. The mass was suspended from the scale by doubled up rubber bands. This caused plenty of oscillations in the data. Can i apply the form mx"(t)+γx(t)+kx(t)=Fcosωt to this situation...

Can anyone tell me if engine cylinder weight lowers, does it make change in fuel consumption or the power of engine?

A long, thin metal (massless) bar is rotating in a circle at constant velocity, perpendicular to the axis of rotation. A weight is placed on the end of the bar such that there is no vertical movement of the weight or bar. What force counteracts the force of gravity on the weight?.

Homework Statement A block weighing 9.3 N requires a force of 3.7 N to push it along at constant velocity. What is the coefficient of friction for the surface Homework Equations Ff=μ*Fn The Attempt at a Solution So the 3.7 N to push is the Force of friction so 3.7=μ*9.3...

If I make 2 wheels of identical size and weight, so that the only difference bewteen the 2 is that wheel A has most of its weight at the center of the wheel and wheel B has most of its weight equally distributed on the circumference of the wheel: 1. Which wheel would spin longer if both...

Wondering if anyone has a good simple formula for rolling a weight up an incline? and the actual pull required for a given weight. The situation is a marine railway comprised of railroad rails laid at approx. 2.68 degree slope into the water upon which a rolling frame, weighing approx...

Homework Statement An object has a weight of 250N, when weighed by spring balance. The same object is fully immersed in water, then the spring balance reading shows, 150N. How to determine the relative density of the object.Homework Equations Archimedes' principleThe Attempt at a Solution...

Imagine an athelete that weighs 180 pounds (81.6 kg) is able to jump 20" (0.51 meters) vertically. How high could he jump if he were able to decrease his weight to 170 pounds (77.1 kg)? I think the basic idea here is to find out, given the mass, what force is required to reach the specified...

There is a tricep machine which is basically a pulley, with some rope connected to a stack of weights and a bar for you to push down on using your triceps on the other end of the rope. How is it possible that if I'm 140 pounds, I can lift like 180 or more on that machine? If I want to want...