Forces Definition and 1000 Threads

Homework Statement How hard must she pull downward to raise herself slowly at constant speed? The mass of the person plus the bucket is 75 kg . The Attempt at a Solution Hey everyone, so I've answered this question and it equals too half her weight. W=2T, but i just want to intuitively...

I am stuck on the questions, 5.3.10 and 5.3.11 which are part of a chapter on dimensional analysis in fluid mechanics by Streeter. Question 5.3.10 (see also the attachment): It asks me for the given fluid dynamic problems, where is the inertial force not important. It lists several fluid...

I have this question which I need to solve . But I am unable to. Suppose I have a current ring of radius R and current I (constant). at a distance x from the centre of the ring, I have a iron disk (radius r and thickness t) present in the plane of the ring. This disk will be attracted to the...

Homework Statement My professor said that since gravity pushes down any object on earth, the objects themselves push up against earth. Intuitively this is difficult too grasp, can anyone give an example or anything to help me out. Thank you

Homework Statement I have the following problem to solve: A 1.8m board is placed in a truck with one end resting against a block secured to the floor and the other one leaning against a vertical partition. The angle the Determine the maximum allowable acceleration of die truck if the board...

having major issue with this question. Homework Statement a wooden crate of mass m= 60 kg sits on the horizontal surface. the coefficient of static friction between the block and the surface is u=0.5 . an external force P = 220 N, is also applied to the block in a direction parallel to the...

Hello, This is an advanced forces problem from introductory Calculus with Physics. I have mostly solved the problem I am posting here but am just missing a force on my diagram somewhere. M. The jpeg below "MassCartTheProblem_1.jpg" shows a picture of the situation and the goal is to find the...

Homework Statement Homework EquationsThe Attempt at a Solution For ##0 \ge \theta \ge \pi/2## Forces on the ring, ##Mg + 2N\cos \theta = F\qquad 1## Forces on the beads ##mv^2/R = - N + mg \cos \theta## By conservation of energy when the bead has fallen through some angle ##\theta##...

Hi, I saw this video and I can't explain why the magnet is propelled to the end of the coil with such a huge force. Can someone explain it in clear terms. I also tried to use Flemings left hand (or right hand) rule but it did not give me a satisfactory answer. Thanks, SM

Hi, I know that if you put a dipole and a neutral molecule at a certain distance, there is the Debye's force that attract them. If you put the same molecules in the first position, they will attract another time. I know this can be a stupid answers, but what's the font of that energy? The...

Okay...If we consider two bodies which are perfectly rigid (meaning they can't deform under any conditions), let's say a ball and a wall...If we throw the ball at the wall, will the ball bounce back?Any answer in terms of action/reaction pair will be appreciated...

Hi everyone! I have few questions which I think might actually be simple, but I would like some confirmation if possible. Here's the situation: I am doing a research project for my MSc. in Forensic Anthropology. The goal of my project is to study the marks left on bones by bladed weapons (in...

What causes Strong and Weak Forces? I know that they bind certain things around in our universe but what causes them?

I was wondering why the arrow of time can't be defined by the direction in which the forces hold their observed values. It seems to me that if the arrow were to be reversed this would necessitate a reversal of the forces' ability to attract or repel. For example: wouldn't gravity have to start...

Homework Statement An elevator containing three passengers (with a mass of 72 kg, 84, and 35 kg, respectively) has a combined mass of 1030 kg. The cable attached to the elevator exerts an upward force of 1.20 x ##10^4## N but friction opposing the motion of the elevator is 1.40 x ##10^3## N...

Homework Statement In a two-dimensional tug-of-war, Alex, Betty, and Charles pull horizontally on an automobile tire at the angles shown in the picture. The tire remains stationary in spite of the three pulls. Alex pulls with force \vec{F_A} of magnitude 220~N, and Charles pulls with force...

The general Ampere force law equation given by Maxwell is: According to Maxwell, all terms containing function ##Q(r)## will vanish after closed integration w.r.t. ##s'## because they will get reduced to functions of ##r## and the upper and lower integration limits will be same since the...

Homework Statement A large 30000 L aquarium is supported by four wood posts at the corners. Each post has a square 6.00 cm x 6.00 cm cross section and is 90.0 cm tall. Take Y=10^10 for wood Homework Equations ΔL = FL/AY F = ma ρ = m/V The Attempt at a Solution So the total area is 0.06 * 0.06...

Homework Statement A block of mass M = 0.5kg, attached to a spring of elastic constant k = 3N/m on a vertical wall, slides without friction through an horizontal air table. A disk of mass m = 0.05kg is placed on the block, whose surface has a coefficient of static friction \mu _e = 0.8. What...

I am doing a review for a Dynamics exam, but I am having trouble with this one question (below). Please note the top of the picture contains the answers. What I have done is make a free body diagram that includes the tension of the cable and the weight of the rider/swing. So according to my...

Homework Statement Two spheres, with 0.5g each, are hanging by 30cm threads, tied on the same spot. The same electric charge is communicated to each sphere; in consequence, the threads move apart until they are about 60^\circ from each other. What is the value of the charge? \theta =...

I'm trying to find some basic physics information. Suppose you have a (massless) beam, supported at two points, 10 feet apart. You have a force (m*g) of 100 Newtons resting on that beam, say 4 meters from the left point (6 meters from the right)... How much force does that exert on each point...

Homework Statement [/B] I am trying to understand why books always point as a fact that hydrostatic force on the bottom of a open liquid filled tank doesn't depend on the force due atmospheric pressure because they these forces cancels each other. Homework Equations [/B] P=[P][/o]+ρgh F=P*A...

Classically... interactions are referred to as forces, then after it is quantum(ized) or quantized, it becomes fields... so strong force becomes strong field, weak force becomes weak field, and electromagnetic force becomes electromagnetic field, gravitational force becomes gravitational field...

Homework Statement Determine all member forces and state if they are in tension or compression, in particular I am looking for member AE and AB[/B] Homework EquationsThe Attempt at a Solution Ok so we are supposed to redo the problems from our exam, only I can't figure out how to find the...

Whether the diameter/radius of pulley affects the force required in lifting a weight?

Homework Statement A ball rolls down a ramp which forms a quarter circle of radius 0.5m. The ball weighs 25g. The bottom of the ramp is 1.5m above the floor. Assume no friction between the ball and the ramp. Assume no air resistance. what is the force exerted by the ramp on the ball? whatis...

I'm trying to just find the hydrostatic force on the hinge of the gate in the image attached, and while not labeled, the thickness out of the page is ##w=5##. My thoughts are to set up this integral $$\vec{F}_p = \iint \rho g y \hat{n}\, dA = w \rho g \int_0^8 y \left(...

Hello all. i am after some help and hopefully you are the right people for this! i have a problem will a kitchen wall cabinet. i can only get fixings which rate at 40kg, but i work out my cabinet fully loaded (including self weight) could be 95kg. i have attached a drawing which hopefully...

Homework Statement The thick arrows represent forces exerrted upon the mast Let ## \vec{r_2} = ~~the~~ longer~force~ vector~~## ## \vec{r_1} = ~the ~shorter ~force ~ vector## correspondinly ## \vec{R_2} = cable ~~2## ## \vec{R_1} = cable~~1 ## r_1 is in the same direction as R_1 r_2 is in...

Homework Statement A comet moves around a stat in ##xy## plane along elliptical orbit, described by $$ 0.16 x^2 + y^2 = 4 $$ where ##x, y## are in ##AU## 1) Sketch the comet in the ##x,y## coordinate system denoting all orbit parameters 2) Find the semi major and minor axes of the orbit...

Hi all, For my final project at university, I am required to design a new swing arm for a Gs500 Motorcycle. I have come up with a C sectional concept when regarding the side beams and will insert X shaped reinforcement throughout the areas of less strength. My main problem is inputting the...

Homework Statement Homework Equations equivalent tension coefficient tDE= applied force/distance between points D and E = 17/SQRT(1[^2+2^2+4^2) = 3.7097 The component of the 17kN in the x-direction = Δx X tDE = -1...

Hi! So I'm building an electromagnetic bicycle where the frame is levitating over the wheels, thus reducing the rolling friction to almost zero by removing the bearings. Magnets have also been placed alongside the wheels to provide side to side stability. Black is the frame, red are the magnets...

Hi Guys, I am trying to calculate the load transferred on the beams and then to the four supports (two under each beam) from a cargo (in this case say a box) to be stored in a yard. I have to check the suitable beam to be used and the load transferred to each support. Thanks in advance. :)

I've drawn the diagram of the forces exerted on and by a block resting on a floor. For now, it seems that the forces exerted on the block are balanced - thus it doesn't accelerate. The forces exerted on the floor are, however, not balanced. The floor is not accelerating downwards, I must then...

Homework Statement "To get up on the roof, a person (mass 70.0 kg) places a 6.00-m aluminum ladder (mass 10.0 kg) against the house on a concrete pad with the base of the ladder 2.00 m from the house. The ladder rests against a plastic rain gutter, which we can assume to be friction-less. The...

If a particle is in the state of rest on the ground , and I apply a force such that it produces an acceleration 4.9 ##\frac{m}{s^2}## upward , will it move upward , considering there's gravitational acceleration 9.8 ##\frac{m}{s^2}## in the downward direction, or will it remain at rest?

Homework Statement I made an apparatus of a rectangular prism dangling from a vertical string from one side while the other is touching the ground. The relationship I'am trying to find is between the angle of the prism relative to the ground and the normal force exerted up wards. I am stuck on...

If gravity is as we know a weak force and magnetism is a strong force, would it be possible to use electromagnetism to propel an object fast enough away from the Earth's surface to escape the pull of gravity and at least put an object in orbit. I assume you would need a long horizontal then...

Homework Statement Find maximum forces in one given jack assembly. If I don't make it any easier, I will have 15 unknown forces, so I tried to just take the weight forces at the top...is it an okay assumption? If not, what should I do? My attempt on a solution is underneath. Thanks for tips and...

I wonder, do you think it's possible to shoot fire, some sort of energy from your hands or eyes; like in comics or cartoons? Obviously we can generate fire from our hands by rubbing them together really fast, and we generate heat from our bodies, but can we also channel these energies like in...

I was talking to my Physics teacher about this at lunch. If I was to have an rc Helicopter which i had hovering perfecting (if only i had the skill) on a train at rest. What would happen in terms of the position of the helicopter as the train accelerated? Would is stay at the same point in...

Homework Statement Block A, with weight 3w, slides down an inclined plane S of slope angle 36.9 degrees at a constant speed while plank B, with weight w, rests on top of A and is attached by a cord to the wall. If the coefficient of kinetic friction is the same between A and B and between S...

Homework Statement A small car with mass .800 kg travels at a constant speed of 12m/s on the inside of a track that is a vertical circle with radius 5.0m. If the normal force exerted by the track on the car when it is at the top of the track is 6.00N, what is the normal force at the bottom of...

Homework Statement 1) Are F and F' as shown in figure, the action-reaction forces between the two boxes? 2) What is the action and reaction force between the two boxes? Homework EquationsThe Attempt at a Solution I think F = 28N and F' = - 28 N Simply adding the action- reaction forces for...

Thread for context this question came up in: http://ecomodder.com/forum/showthread.php/how-improve-fuel-economy-tonneau-cover-124-6.html#post535358 I'm guessing we will want the answer in pounds, perhaps FT/Pounds. Ballpark numbers on horizontal, vertical and or down-force and or lift. Just...

Hello guys! Can I view graphs of Piston Force versus Piston Displacement or time, in a combustion piston? I would be interested to see how the graph varies by manipulating parameters such as fuel amount, air amount, piston geometry, rpm, etc Thanks!

Dear Experts, Trying to analyze the work done by internal forces in a very simple two particle system which is attracted to each other with a constant force, i performed calculations based on two frame of references, 1.The center or mass frame of reference and 2. Frame of reference of one of the...

Homework Statement We have an electric dipole with moment P=2*[10][/-5] pointing in x direction. What is the force experieced by dipole at origin when a point charge Q=3*[10][/-4] is located at (0.014 m ,0,0) Homework Equations 1. [E][/dipole]=(1/4π[ε][/0])(2p/r3) 2. p=qs 3. F=qE 4. τ=pEsinϑ...