Forces Definition and 1000 Threads

TL;DR Summary: Solved the biceps, but having trouble finding the reaction force now. I eventually calculated, using the moment, that the force exerted by the biceps is 1536 N (this is correct according to the model solution), but the calculation of the reaction force is more difficult. I was...

From Khan Academy; “As truck moves with constant velocity down the road, its acceleration is zero. Therefore, the net force acting on the box must be zero.” Which forces are involved in a truck moving with constant velocity (and therefore no acceleration)? The gravitational force and the...

So if I understand correctly the forces acting on the sphere are ##\vec{F}##, the normal force, friction, and the weight of the sphere. In order for the conditions of static equilibrium to be met the net torque must be zero. The torque about the center of the sphere created by the normal...

Hello, I have tried to resolve this using the fact that we consider the weight to be normal, so I resolved the tensions in both the strings using an angle of 45 degrees. Upon solving these simultaneously T2*cos(45) + T1*cos(45) - 10 = 0 , T2*sin(45) - T1*sin(45) = 0, I have gotten T1 = 5√2 and...

Hi, In refreshing up on some topics regarding Mohr's circle, I came across this problem and can't seem to understand how the forces for the sheaves were obtained. The problem contains a shaft that has two V-belt sheaves rotating in opposite directions. The shaft has a Torque of 1100 lb-in and...

I would like some help with the first part of this problem. I have calculated the distributed load to be 3.82kN down as the integral of f(x) from 0 to 6 gave me that value. I found it to be 3m to the right of A as well. As such based on an analysis beam ABCD I calculated A(y) to be 3.67kN...

My answer is ## \sqrt((300^2)+300^2)## = 424 after superimposing both ##cos13πt## and ##sin13πt##, After which, the overall of amplitude of superimposed of all 4 forces are ##\sqrt( (434^2)+ (500^2) + (600^2))## = 893, correct me if I am wrong

Hi, apart from the interesting wording of this question, I'm struggling to understand the concept of what we need to do here. I started by having three equations (summation Fx, summation Fy and Moment about Y). I also calculated the two reaction forces about A and the one rection force about B...

I hope i made clear what i mean and i really hope i can get my answers here Thank you very much for answering already

I know That the velocity of each particle of the thread along the thread must be ##v_{0}## since the thread is inextensible. Now let's say the bead moves with some velocity ##v## For the particle attached to the bead to move with a velocity ##v_{0}## along the thread: ##v##cos##θ##= ##v_{0}##...

G=mg (vertical down), F=kx (from the spring to the cylinder)

So I basically identified two constraints, 1) The string cannot be slack, therefore the acceleration of block down the incline should be equal to the acceleration of the wedge. 2) The block must always stay in contact with the wedge. Hence, the acceleration of the block normal to incline must...

Hi, I recently bought a folding bike and it turned out over time that its weak point is the main hinge where two bolts (vertically placed) are located. I've had the lower bolt break twice during a ride, leaving a part of it stuck inside the hinge thread. It's clear that the forces applied were...

By applying some simplifications, the power ##P## of a body moving at a speed of ##v## at an incline of ##\alpha > 0^\circ## can be expressed as: ##P = P_{acceleration} + P_{friction} + P_{gravity} + P_{air} = (ma + mgsin(\alpha) + C_{rr}mgcos(\alpha) + 0.5C_dA\rho v^2)\cdot v## If we would...

I get that the speed is 3.1 m/s, the forces in the rod are 38 N downward and 58 N upward, and that the force on the axis is 49 N.

I need to calculate the forces in each of the beams in one of the two equal cross sections of the truss attatched in the picture. The second picture is the cross section of the truss. As you can see on the 3d picture of the truss the loads are attatched with equal distance inbetween the 2...

Normally action reaction forces do not move things. In this problem they move. I wish to discuss in what way these so called constrain forces contributeto motion or kinetic energy L. Do they do wirk. Yes then why no then why not?

Apparently the melting point of IBr is 42 Celsius whereas that of IF is -45 Celsius. As Fluorine is highly electronegative, the dipole-dipole bonds in IF should be a lot stronger than in IBr. So I am wondering what forces are responsible for the huge disparity in melting points - the complete...

I did classical mechanics a while ago and I was going over some stuff that I wasn't sure if I understood correctly and now I've come over this one. It says that work done by conservative forces is equal to the negative difference in potential energy. Or, ##W_c = - \Delta U##. And I've really...

For the first point I need to draw a free body diagram of the block and balance the forces: I chose to use as axis the ones that have the same direction of the components of the weight force; y-positive upwards, x-positive leftwards ##\begin{cases} \Sigma F_y=0 \\ \Sigma F_x=0 \end{cases}## ##...

For this freebody diagram showing a cloth being pulled from underneath a block, if we take the moment about the normal force: m*g*L/2 = 0, there is no force counteracting the moment from the weight of the block. But if we take the moment about the center of gravity: N*L/2 - Ff*H/2 = 0 How do...

I'm currently reading Jason Thalken's Fight like a Physicist, and I think so far they gave one of the most intuitive explanations of the practical difference between Momentum and Kinetic Energy, but I'd like to just conceptually reinforce it and make sure I have it right. So from what I...

I understand that if the sun where to 'disappear' then it would take several minutes for the us on the earth to notice as the light takes time to travel. Does this mean that it would also take the same time for us to notice that the gravitational (or electromagnetic) force would disappear too...

For point one I analyzed all of the forces, called the tension on the right ##T_2## and the left one ##T_1##, and taking as positive the clock-wise and upwards directions I found: $$\begin{cases} T_2 - mg = ma \\ N_2= T_2 + M_2g + T_1 \\ N_1= M_1g - T_1 \\ τ_{T_2} - τ_{T_1} = I_2 α_2\\ τ_{T1} =...

I'm with a home study structural engineering as an electrical engineer. The assignment that I am trying to do is calculating a frame to support a large pipe with a weight of 32,000 kN distributed across eight legs. ( so it on a job site) I've performed a detailed analysis of the forces using...

The question is regarding this image, I understand the two 50N forces provide a clockwise moment of 40 x 10^-2 x 100 which gives option D, as this moment must be balanced by the moment given by T. Now my question is, how is the net force on this system equal to 0? It says it is in equilibrium...

TL;DR Summary: Forces on Elliptical Current Carying Loop Please consider Current carrying elliptical 1-turn coil as shown in the picture. Is it true that due to forces from the current , the elliptical shape of the coil will tend to become circular ? Thank you...

15cos25 - 0.25N = ma.

My AP Physics notes state that counterclockwise is generally positive and clockwise is generally negative. This makes sense to me and means forces on opposite sides of the pivot point which act in opposite directions will work together, and this is the logic I applied to answer the problems...

Fx = 0 = ABcos(a)+BCcos(b)-BDcos(30) Fy = 0 = ABsin(a)+BCsin(b)-BDsin(30) == Fx = 0 = ABcos(a) + 3.2737cos(b) - 3.738 Fy = 0 = ABsin(a) + 3.237sin(b) - 2.158 But i cant find a third equation to use. I've tried a+b = 90 but that produced a number of errors. Thank you. Edit: angle b is the...

I used Rx = 100cos(0) + 200cos(90) = 100. Ry = 100sin(0) + 200sin(90) = 200. tanO = Ry/Rx = 2. Therefore O(theta) = inv tan (2) = 64 degrees.

for 4kg box: Fx = T m1a=T (4) (2.50) = T 10 = T for 6 kg box: Fx = Fa - T m2a = m2a - T 15 = 15 - T 15-15 = T 0 = T I assumed the tension would be the same for both boxes, they are supposed to be, so what did I do wrong and is the answer 10 or zero?

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So, my question is pertaining more to a specific part of this problem than actually calculating ##P## which I get to be ##P = \frac{kh}{2} - mg##. But I need ##P## in terms of a multiple of ##mg## so I need to find ##k##. The solution attached uses the fact that when the object comes to a rest...

I found the internal force Vxy 25 +6 =31kn. , bending moment Mmin -qb2/2 , M min- 14 kNm. delta =M/W I can't find Mmax and tau= V/As. So I need help to find Mmax and As wall area, how to find.

In this problem why do I need to use this formula? F – F12 = m1 a along the x-axis. What does F12=-F21 stand for? And I don't understand when they say to find the magnitude of the forces between the two blocks

I think the first part is F = mxa? But given the jib is resting on a turntable at a certain distance, does that mean the longer and shorted ends experience different loads? Especially when the shorter end has a 16T counterweight? The second part, I have no idea how to calculate this nor the...

I don't even know how to begin this. I know that I need to somehow account for the drag force that duck 3 is causing on the first 2, but I don't know how to deal with that. I am asking for someone to help me get started, not to give me the answer.

Hello, Why isn't the forces resultant on a "large" molecule (by small molecule: water for example) zero? The reason for this Brownian motion is the thermal agitation of the water molecule. If we talk about white and Gaussian noise in electronics (due to the thermal agitation of the electrons)...

Frictions are neglected in the system pictured. Here, a 1kg object released from above moves the car underneath. When this object falls off the car, what is its speed in m/s? This question was asked from momentum conservation, but I didn't want to do it from there. Can you solve the question...

Hi, I had no problems calculating parts a and b, but I am having problems with task c For ##F## I got the following, with ##\vec{r}= \left(\begin{array}{c} x \\\ y \\\ 0 \end{array}\right)## , ##\vec{r}_1= \left(\begin{array}{c} -a \\\ 0 \\\ 0 \end{array}\right)## and ##\vec{r}_2=...

Let the left string be T1 and the right string be T2. Pretend that the masses are NOT equal and that the total mass on the left is 3mg and the total mass on the right is 2mg. My first thought: Net torque = 3mgR1-2mgR1 Actual solution: Net torque = (T1-T2)*R Once again, the force that's used...

I was going through the stress-strain curve and I realized that strain is taken as the independent variable and stress as the dependent variable. In reality is this true or is it the other way around?I saw a lot of answers on Quora that say that strain is the cause and stress is the effect. But...

I've been trying really hard to calculate the forces between a permanent magnet that is within an electromagnetic field. I have tried every formula under the sun, but it seems I am just not using the right ones, as my results always end up nonsensical. To be clear, I am trying to understand the...

Hey all, I'm either overthinking it or too tired but this problem should be an easy one to figure out but I'm stumped embarrassingly. Say in the photo above is a lever arm. I'm trying to backtrack to calculate the force a user must input (yellow) against a force (red). It can pivot around...

I have difficulty understanding the extension of the fundamental laws of material point dynamics to systems. Example 1: Consider a system consisting of two material points. Suppose that the two forces acting on the two constitute a pair of forces of nonzero arm. The resultant of the forces...

While not exactly correct, we will continue to use Newtonian gravitational force and tension force in the lab frame. We will not concern ourselves with GR, besides the approximation is reasonable for low velocity and small mass. In the lab frame, the forces acting on the pendulum is weight and...

The problem is based on a similar thread. In fact, the first question is extremely similar. However, the second question is the one I consider more interesting but I posted the first one too for context. If this was just 1 pulley and two masses, then equilibrium is only possible if both masses...

Would it still work in a similar manner as an actual electroscope where you would charge it either positively or negatively and then observe attractive or repulsive forces or is there an easier and more efficient method?