Weight Definition and 1000 Threads

If I know an object has a mass of 5 kg, and I want to find its weight on earth, I multiply it by 9.81 - right? That equals 49.05 kg. Now, if I want to convert it to Newtons, I multiply it by additional 9.81 So it would equal 481.18 [N]? Is that right?

Homework Statement I am trying to help my lil bro (12 yo) with some physics. I've never been good in physics and now it's been more then 10 years that I've been to elementary school. I've helped him with some stuff but there's this one question that i don't understand and there's very little...

I have 5 different types of balls made out of different materials, all similar but not identical in weight, and all of the the same size. What is the best mechanism to sort these by weight? I can use any mechanical device to sort these balls, such as seesaws, etc. What is the most efficient way?

Homework Statement A muscle builder holds the end of a massless rope. At the end of the rope, a 15 kg ball is hung as shown in the figure. What is the tension in the rope if the angle \theta in the drawing is 4.5^{}o? Homework Equations g = 9.8m/s^{}2 F = mg Trigonometrical functions The...

A friend asked me a question recently... If you were washed up on a desert island - with nothing but yourself, and what the island offers (your standard desert island I guess) - how could you work out a system for mass, distance and time? I've assumed that a system could easily be made -...

Homework Statement so in my physics class, we are learning about the 3 laws of motion and all that jazz bla bla bla, i get all that stuff, just not the stuff where it comes to math. i suck at math! so we had homework, no duh, and well I am stuck, can i please have some help! anyone?? hear...

so in my physics class, we are learning about the 3 laws of motion and all that jazz bla bla bla, i get all that stuff, just not the stuff where it comes to math. i suck at math! so we had homework, no duh, and well I am stuck, can i please have some help! anyone?? hear is the problem: An...

Homework Statement A 1.25-kg mass stretches a vertical spring 0.215 m. If the spring is stretched an additional 0.130 m and released, how long does it take to reach the (new) equilibrium position again? m_object = 1.25 kg A (amplitude) = 0.130 m (since the spring has a new equilibrium at...

Homework Statement http://www.engr.mun.ca/~neil/1010/prob11/set2.pdf" In the first problem in the link above, why is the weight pointing upwards instead of downwards? I thought there will be a different force prolly called Fae pointing upwards with the weight pointing downwards. Thanks

Homework Statement A parachutist relies on air resistance (mainly on her parachute) to decrease her downward velocity. She and her parachute have a mass of 55.0 kg and air resistance exerts a total upward force of 620 N on her and her parachute. A.) What is the weight of the parachutist? B.)...

I am lean by nature and an avid cyclist at that. I noticed that any food I eat gets put to work during my extended spinning session. I would like to gain some more muscle in my leg area to give me more power during hill climbing and accelaration in a race. I don't know what kind of muscles I...

Homework Statement A box with a height L, and a cross sectional Area A is floating between two fluids of densities p1 and p2. Determine the mass of the box using ho, h1, h2, p1, p2, and A. Homework Equations F= pVg The Attempt at a Solution In the file attached I drew my free...

Homework Statement A weight lifter (mass 75Kg) raises body's centre of mass by 0.4 in the process of lifting a barbell weight of 70kg to the height of 1.04m above the ground. Calculate the total work done in lifting the weight.The weight is raised in 0.2 seconds; hence calculate the power of...

Hi there, If there are 2 bicycle riders who use exactly the same type of bicycle, start at the same spot but one rider is 100kg and another rider is 50kg.. would the heavier rider coming down the slope faster than the lighter rider? basically, I just want to know if the weight would affects...

Homework Statement In a certain structure, the cables C1, C2, and C3 (Figure) can each carry a weight of 100kg, and C4, C5, and C6 can each carry 50kg. Weights are suspended at R, S, and T. What is the maximum total weight the structure can carry? PS1: (Ignore the weight of the...

You could gain a lot of weight and still have very little body fat! Of course, you'd need to do it for a very long period of time (for the D2O to replace all the H2O in your body). But would there be health risks? haha.

Homework Statement A compound with a molecular weight of 110.1 g that contained only C, H, and O was analyzed by combustion. the combustion of a 5.19 g sample of the compound resulted in the formation of 12.4 g of carbon dioxide and 2.55 g of water. What is the molecular formulas of this...

What formula would one use to determine the centrifugal force at the tip of a rotor of 35ft diameter, rotating at 392rpm? Would any other factors be necessary, such as blade thickness, weight, etc? A pilot I work with doesn't believe the weight at the rotor tip would be measured in tons. I...

I'm Canadian, and I'm trying to convert the draw weight (55lb-65lb) into something I can put into 1/2kx^2. Please help!

First off, please excuse my general lack of physics knowledge, it's been 10 yrs since one year of it in high school ... but I can usually follow along pretty well once pointed in the right direction. I've been curious about the relationship of wheel weight and diameter in relation to distance...

can someone help me with this. you have a free falling weight such as a 500 lb. steel ball dropping from 3 ft. How much force will the weight produce in ft. lbs. or tons when hitting the ground. what is the formula for figuring this. Also, will the amount of force double if dropped from 6 ft...

Hi all! I have a few questions about physics and weight training. I searched around a bit but only found these two threads: https://www.physicsforums.com/showthread.php?t=451027" https://www.physicsforums.com/showthread.php?t=381643" which don't totally cover my interests. I know that...

Homework Statement Steel object is pulling uniformly through the ice with applied force 2 Newtons. Find object's weight (P), if k of friction is 0.02 Homework Equations F = 2 Newtons k = 0.02 P - ? F = m*a P = m*g The Attempt at a Solution I drow all forces and made this: ma =...

By definition, the difference between Mass and Weight is easy to comprehend. However, I am really confused, confused to the level I feel like ripping all the hair out of my head, with spring balances: After researching a lot, I think that as I step on a spring balance the spring will extend...

Homework Statement A 500g mass is submerged in water, displacing 57.6mL of water. The force of gravity on the weight when submerged is measured to be 4.35N. The actual weight should be 4.9N. (remember that the density of water is 1000kg/m3) (the weight is being held in the water by a spring...

Homework Statement What is the apparent weight of a rock submerged in water if the rock weighs 58 N in air and has a volume of 1.8 * 10^-3 m^3? And then as a continuation: A rock weighing 57 N with a volume of 2.3 10-3 m3 is submerged in a liquid with a density exactly twice that of...

Hi all, when you try to lift explosively a weight there is a acceleration phase and obviously a deceleration phase in order to stop the weight at the end of range of motion(end of repetition). Is it alright to assume that at the deceleration phase less force than the weight is applied?

hey guys I am new here so i would first like to say thanks for reading my post. i got this question that I'm stumped on so please help me thank you! A *12 kg crate is sliding at constant speed down a smooth platform that makes a 35. degree angle* with the horizontal. Calculate the weight...

Imagine an object is resting upon the floor. The object is pushing the floor with a force mg, which is vertically downward. The floor is also pushing the object back with the same magnitude of force but it is vertically upward. My question is: which one of these force is called weight? My...

Homework Statement Say functions f and g continuous on [a,b] and happen to be orthogonal with respect to the weight function 1. Show that f or g has to vanish within (a,b). Homework Equations f and g are orthogonal w.r.t. a weight function w(x) if the integral from [a,b] of f(x)g(x)w(x)dx = 0...

Homework Statement Scenario: A block of mass m hanging on the end of a vertical spring with spring constant k Homework Equations When the spring has come to rest: Vertical eqm: weight = force exerted by spring mg = kx Energy conservation: loss in GPE =...

Homework Statement A man, holding a weight in each hand, stands at the center of a horizontal frictionless rotating turntable. The effect of the weights is to double the rotational inertia of the system. As he is rotating, the man opens his hands and drops the two weights. They fall outside...

Homework Statement I was just websearching and came across this interesting demonstration. http://demonstrations.wolfram.com/AMassiveBarOscillatingBetweenTwoIdenticalRotatingSupportRoll/ Homework Equations I wanted to define the normal forces N1 and N2 based on their position x(t) from...

weight or mass? I have a friend here who is totally convinced that the scales we use at home to weigh ourselves our actually measuring our mass not our weight...Could somebody please enlighten her hahaha

Find the weight of a pumpkin hanging from two scales, if scale one reads 33 N, scale two reads 49 N, and the angle θ between the strings coming from the two scales is 131 degrees. http://a1.educog.com/res/msu/plough/physlibrary/graphics/pumpkin.gif I attempted to do this. I used law of cosines...

Does the volume swell ratio relate to the weight gain when a crosslinked polymer is emersed in a solvent? Is it as simple as calculating (delta V) = (delta w)/density?

Does an object gain weight? When a person is in an elevator and the elevator begins to go up...Does the person actually gain weight? I know mass will not change obviously, but does the variable "g" vary due to acceleration?

Homework Statement I'm trying to figure out how to compute the average molecular weight of a gas mixture (nitrogen dioxide and dinitrogen tetroxide). I think I'm suppose to use this equation: M(mix)=X(NO2)M(NO2)+ X(N2O4)M(N2O4) , where I would just need to calculate the mole fractions and the...

Homework Statement On takeoff” refers to after the plane has left the ground. On takeoff, the combined action of the air around the engines and wings of an airplane exerts a(n) 8445 N force on the plane, directed upward at an angle of 50.2◦ above the hori- zontal. The plane rises with...

The lab that we did measured mass vs. weight. We took eight objects and found that mass using the triple beam balance (units in Kg) and the found the weight using a spring scale (units in Newtons) Homework Statement Assume that this experiement had been performed on the moon istead on...

Homework Statement Because of Earth’s rotation about its axis, a point on the Equator experiences a centripetal acceleration of 0.034 m/s2, while a point at the poles experiences no centripetal acceleration. What is the apparent weight at the equator of a person having a mass of 118.1 kg...

Correct? Please let me know if my logic is off. Thank you =] Given Problem At the bow of a ship on a stormy sea, a crewman conducts an experiment by standing on a bathroom scale. In calm waters, the scale reads 180 lb. During the storm, the crewman finds a maximum reading of 234 lb and a...

1. A car has a wheelbase of 9.57 ft. At a weigh station, the driver puts only the front wheels on the scale and measures a weight of 2091 lb. The driver then moves the car and places the rear wheels on the scale and measures a weight of 1930 lb. Find the total weight of the car. Find the...

Homework Statement The two angled ropes used to support the crate in the figure below an withstand a maximum tension of 1800 N before they break. What is the largest mass the ropes can support? picture of the crate and ropes...

Homework Statement A car of weight 1490 N operating at a rate of 121 kW develops a maximum speed of 49 m/s on a level, horizontal road. Assuming that the resistive force (due to friction and air resistance) remains constant, what is the car’s maximum speed on an incline of 1 in 20; i.e...

Few quick questions, too lazy to look up this info my self: 1. Whats the max molecular weight for a single polymer strand of styrne (i.e what's the max number of styrenes you can link up). 2. Anyone know about the industrial process to produce ABS? 3. What is a good solvent for Styrene...

Homework Statement Does a falling object posses weight? Homework Equations F=mg The Attempt at a Solution I thought yes because it still has a mass and is accelerating due to gravity. However, the answer is No. If anyone could shed some light on this I would greatly appreciate it.

I have the solution of this problem, but I would like someone to give me some guidance on how to begin solving the problem. Thanks! A 1520-N crate is to be held in place on a ramp that rises at 30.0° above the horizontal (see Fig. CH 5-6.15). The massless rope attached to the crate makes a...

Homework Statement A cylindrical buoy with diameter 18 in. floats in water with its axis vertical. When depressed slightly its period of vibration is found to be 2.7 seconds. Find the weight of the cylinder. Homework Equations I know that an object submerged in water is buoyed up by a...

Homework Statement A rear-wheel-drive car supports 42% of its weight on its two drive wheels and has a coefficient of static friction of 0.80. What is the car's maximum acceleration? Assuming infinite engine power, how long will it take the car to reach 105 km/h? Homework Equations F_g =...