Forces Definition and 1000 Threads

I feel like it would go on the side of the energy the object has where it starts - an object dropped off a cliff would be modeled U - W = K but an object thrown upwards from ground level would be K - W = U. I am not sure though.

Statement: My friend represented this sentence "Two forces have magnitude of 3N and 5N, and have an angle of 60 between them" into this diagram: But why didn't he represent like this?:

So looking at the solution, FBD for A makes sense: Normal points inwards, gravity and friction oppose each other, with friction pointing up. B confuses me: the solution says there is only Normal and gravity pointing downwards, but if "the sphere rolls without slipping during the entire motion"...

Problem Statement: What's your result of ##X_A##? I find mine is different from the standard answer. Relevant Equations: My answer for $$X_A =5 kN$$ Problem Statement: What's your result of ##X_A##? I find mine is different from the standard answer. Relevant Equations: My answer for $$X_A...

Hi, A solution contains some ions (charged particles). We are only interested in my exemple to positive ions. It is assumed that these ions acquired some mobility under a concentration gradient. Their direction is A to B. Then these ions encounter/cross an electric field which is oriented from B...

I started off by finding when Fg=Fx: (72)(x)=(31)(9.8) x=4.2193m After this I'm stuck and have a few things I'm confused about: When the penguin's jumping, is there elastic energy? (because the rope's getting compressed? Or maybe not). Also, I know you can use energy conservation, but...

I don't understand why a force would be acting on this rectangular coil at all. The magnetic field of the wire would only induce a force on the coil, if the coil had a current flowing through it. At first I would think that the electric field from the varying magnetic field would induce such...

[moderator note: super size font formats removed.] When a water jet strikes a plate (3m plate) at an angle (like 60 degrees), velocity of water decreases as it travels downstream. I know the major contributor that slows down water is probably wall frictional force but how to quantify this...

Let's say we have a system of two point particles that can interact with each other by forces that are position and velocity dependent. The forces might or might not be derivable from a generalized potential. Assuming Isotropy of space and homogeneity of space and time, what are the constraints...

I am attempting the work out the forces acting on the base of a crane. I am yet to come across forces at the base of a crane and am confused as to how to work out the reactionary/moment forces. Any help would be greatly appreciated.

My physics teacher did not give a clear definition. Is it a force or not?

Why does the pressure we take into account is the gage pressure and not the absolute pressure? Reading Fundamentals of Momentum Heat and Mass transfer by Welty in chapter 2 it says "the magnitude of the force on the element dA is PgdA ,where Pg is the gage pressure" my question is why the gage...

Homework Statement A wedge with face inclined at an angle θ to the horizontal is fixed to a rotating turntable. A block of mass m rests on the inclined plane and the coefficient of static friction between the block and the wedge is µ. The block is to remain at position R from the centre of...

Homework Statement The pulley device is used to hurl projectiles from a ramp (Coefficient of Kinetic friction [mu] = 0.26) as illustrated in the diagram. The 5.0 kg mass is accelerated from rest at the bottom of the 4.0 m long ramp by a falling 20.0 kg mass suspended over a friction less...

When an object is resting on a surface such as the floor, there are exerted on it two forces: The normal force - force of the ground - and the weight (the force of gravity, the Earth pushing the object down), the forces drawn on the left. What are the forces on the right? Are they the same as...

The question asks to calculate the determine the projection of the resultant force of F1 and F2 onto b-axis. However instead, the solution is a projection of F1 on b axis plus F2. Shouldn't the solution involve the projection of R which is 163.4 on to be axis? and for answering that, don't we...

Hi i am posting this to double check my work. Please help and feel free to ask any questions. I posted a picture of my work and what i currently have. 1. Homework Statement Two small insulating objects are hung from strings attached to the ceiling. The masses of each object is 0.0076 kg. The...

Hello all, I understand there are four d'Alembert (fictitious) (non-inertial) forces: 1. Coriolis 2. Centrifugal 3. Linear 4. Angular acceleration. But then I think about the Gyroscopic Effect (I understand how it arises, so that is not the issue). I am wondering if one can "classify" these...

Hi everyone, I'm new here so I hope I'm posting this in the right place. I'm struggling to duplicate the horizontal reaction forces being generated in an L shaped beam. Typically I like to do hand calculations and verify my answer using Solidworks, but in this case I can't seem to wrap my head...

Hello new to the forum. I'm a builder by trade and enjoy studying the concepts behind the things I build. My problem is: A typical concrete post and base panel with a wooden fence. Unit mass approximately 350kgs including the foundation concrete around the posts. 2.0m wide x 2.0m above...

Homework Statement Homework Equations Using dimensional plane in the vertical y and horizontal x. ##\Sigma##Fx = 0 ##\Sigma##Fy = 0 ##\Sigma##Mz = 0 The Attempt at a Solution I have detached the 2 members at B and analyze them both separately. The 14 kip force is throwing me off though...

A 0.160 kg ball attached to a light cord is swung in a vertical circle of radius 70.0 cm. At the top of the swing, the speed of the ball is 3.26 m/s. The centre of the circle is 1.50 m above the floor. a. Draw a free-body diagram of the forces on the ball at the top of the swing. b. Calculate...

Based on the Comex Hydra 10 tests, a diver breathing the correct mix can withstand a depth of 2300 ft, or the pressure of a column of water 2300 feet tall - nearly 1000 psi. Since the diver is buoyant (being the same average density as the water), they are essentially weightless. Not in...

The attached image shows a linkage mechanism with 2 parallel bars pivoted to a fixed base. The lengths of the the bars are equal. A connecting linkage and gears are used to connect it to a 3rd bar. I would like to know how to analyze this linkage system to find the forces, moments and loads for...

I've been reading a book called hyperspace by D.R Michio Kaku. In this book he talks about unifying all the fundamental forces of nature (gravity , electromagnetic force , weak and strong nuclear forces.) My question is, what if they are not unified and we are just trying in vain. I don't...

Homework Statement [/B] A Kuiper Belt object, Ultima Thule, rotates once every 15 hours. It has an estimated density of 1000 kg/m^3. Ultima, the larger sphere, has a radius of 9000 meters. Thule, the smaller sphere, has a radius of 6500 meters. The center of rotation is 4200 meters from the...

I am wondering why gravity needs to be unified with the other three forces into a super-force. Why can't the three forces be seen as interactions between particles in a space-time fabric whose geometry gives the impression of gravity?

I am trying to understand how fluids form particular shapes when put on a solid. In the two figures,what are we taking as a system for the forces? How the resultant of the forces influences the shape of the different fluids?

hi all i have a simple question but answer i don't know how to find :) lets say we have a electric motor with 1kw at 1500 rpm and that is 4.75 N.m when the electric motor is connected to worm gearbox n proportion 10:1 then the speed on output point of the gearbox will be 150 RPM. But this mean...

Hi all, I need to bond the back surface of an elliptical mirror (75mm major diameter and 37.5mm minor diameter) onto a voice-coil actuated mirror mount that is going to be operating at 500 Hz and has an adjustment range of +-1.5 degrees. I need to determine the g-force likely to be acting on...

Homework Statement The goal is to calculate the static forces in the throwing arm of the trebuchet when it's pinned as shown in the image. The counterweight is equal to 1435 Newtons. The mass of the arm is equal to 114 Newtons. Dimensions are shown in inches. The pin is in double shear...

Suppose there is a circle with area 'A' and on one of the faces of the circle a force of 100N is applied and on the other face a 30N force is applied (since all 2D surfaces have 2 faces) such that these forces are opposite to each other, perpendicular to the faces, and forces are equally...

Hi Everyone. New to the forum I am attempting to design a piece of furniture that has opposing forces. A set of opposing stairs that either lower or raise a central platform. The idea is that two people would have to collaborate together to make sure the central platform doesn't sink. Think...

Homework Statement Find the tension in each section of string in terms of ##θ_1##,m and g. Homework Equations Equilibrium of force,dimensional analysis of force. The Attempt at a Solution The support points are at rest and in each points,there are two equal tension force acting in opposite...

So I need to find equations for the force required to tip over a cylindrical object. This is fairly straight forward in the case when the force is applied above the centre of mass, by taking moments about the pivot corner. However, in the case where the force is applied below the centre of mass...

Homework Statement [/B] The total mass of a space shuttle and its launch vehicle is M=2000t. a) What must be the minimum size of the thrust force, to make the rocket move? b) The actual thrust of the rocket is F=30MN. What is its acceleration in the beginning? c) Assume that a mass of a...

Homework Statement Do ionic compounds such as NaCl and K2O have intermolecular forces? 2. The attempt at a solution I got stuck conceptually. NaCl and K2O are ionic compounds. Their basic unit is formula units. They are not molecular compounds. Ionic compounds are held together by...

Homework Statement 2. Homework Equations [/B] So I basically have to establish the non linear differential equation that governs the movement of this robot (relates d and theta): The Attempt at a Solution So I know that we should have the sum of torques equal to...

Homework Statement A mass M1 is sliding across a table with coefficient of kinetic friction μk. A string is tied to this mass and runs over a pulley, drops vertically and is tied to another mass M2 which is falling. The pulley is connected to the table by a support. The pulley is a solid...

Homework Statement A mass of 3kg is acted upon by three forces of 4.0 N, 6.0N, and 9.0N and is in equilibrium. The 9N force is suddenly removed. Determine the acceleration of the mass. Homework Equations F=ma. The Attempt at a Solution My main problem with this question is that I cannot think...

Homework Statement A mass of 50 grams hangs in equilibrium on a string. The mass is pulled aside and upwards by a force of 0.3N which makes an angle of 30° with the horizontal. Find the angle that the string makes with the vertical and the tension in the string. Homework Equations Body is in...

Hi, I am trying to 'size' my first motor to drive a system. I am trying to make a feeder where a PVC pipe is fed as shown. There are 2 vertical rollers, on connected to the motor as shown and an other coupled to a pneumatic piston to keep the pipe under pressure. the frictional force will be...

Hello, In the game of tug of war, the team that wins is the one that exerts the largest force and pulls the other team their way. However, a team can win only if the force they produce is matched by the static friction between the floor and their feet, correct? But what would happen if the...

Homework Statement A) Three infinite, current-carrying wires are arranged as shown below. In terms of the given quantities, determine the magnitude and direction of the magnetic force per length acting upon wire 2. (Part A.jpg attached) B) Three infinite, current-carrying wires are arranged as...

Homework Statement Block A is on top of Block B, both are of equal mass and size. Block B is being pulled by a hook at a constant velocity. There is friction between the table and block B. Homework Equations [/B] What will each FBD look like? Is there friction between Block A and Block B...

Homework Statement An ideal, infinitely long straight wire carries a current I1 and is partially surrounded by a loop of current as shown below (image attached). The loop has length L, parallel to the infinitely long wire. The loop carries current I2. A) Calculate the magnitude and direction of...

So, if the Earth moves slowly through a large hula hoop, sensors attached on the hoop will measure some stresses, which we might call tidal forces. The faster the Earth moves relative to the hoop the larger those tidal forces are. So, if a person falls into a black hole, there are some tidal...

I'm a former physics student and I've been thinking about an interesting problem that eventually led me to the following thought experiment that I'm having trouble resolving. Imagine a two-compartment system, where one compartment is filled with He gas, and the other is filled with standard...

Homework Statement While unrealistic, we will examine the forces on a leg when one falls from a height by approximating the leg as a uniform cylinder of bone with a diameter of 2.3 cm and ignoring any shear forces. Human bone can be compressed with approximately 1.7 × 10^8 N/m2 before...

Homework Statement Homework Equations ∑MA = 0, where A is the pin. Tx = Tcos150 Ty = Tsin150 The Attempt at a Solution I've drawn in the 100kN force of the beam's weight, and identified that ∑MA = 0. I attempted to find the moment arm, but really wasn't sure how do to it, or if it would even...