This tag is for the classical concept of forces, i.e. the quantities causing an acceleration of a body. It expands to the strong/electroweak force only insofar as they act comparable to ‘classical’ forces. Use [tag:particle-physics] for decay channels due to forces and [tag:newtonian-mechanics] or ...

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2
votes
2answers
117 views

How does the Lorentz force work?

How does the Lorentz force work? In the context of a homopolar motor. I am a year 13 student so please keep your answers simple! I am having trouble understanding the Lorentz force; does the magnetic ...
2
votes
1answer
44 views

Rate of acceleration for two hanging masses in two experiments

I conducted an experiment where two masses of different weight were attached by a string and fed through a pulley. The difference between the masses was $0.025\: \mathrm{kg}$. The lighter mass was ...
1
vote
1answer
43 views

Large rotation Euler-Bernoulli beam boundary condition

Is given in Wikipedia as $$EI\frac{d^4u}{dx^4}-\frac{3}{2}EA\left(\frac{du}{dx}\right)^2\frac{d^2u}{dx^2} = q(x) ,$$ where $q(x)$ is the transverse load (assuming uniform cross-section and no axial ...
0
votes
3answers
193 views

Can a feather and a hammer ever touch ground at same time on Earth?

Do you think it is possible to find a way to make a feather and a hammer touch ground simultaneously? Can you make up a device that avoids air resistance? I was thinking of something like (2 x ) two ...
1
vote
1answer
48 views

Electric force between charges in two different media

As far as I know, Coulomb's law of electrostatic force is applicable on two different charges situated in same medium. But if two individual charges are in different media (say one charge on a iron ...
-1
votes
3answers
100 views

Where does the force to stop a constant velocity object come from?

If a ball hits a wall at a constant velocity, it will slow down and eventually come to rest. Since the ball was at constant velocity, it was not accelerating, and so there was no force. Also, the ...
0
votes
2answers
66 views

Who plays the role of centrifugal force in an inertial frame of reference?

It is noteworthy to quote a sentence from my book, It is a misconception among the beginners that centrifugal force acts on a particle in order to make the particle go on a circle. Centrifugal ...
0
votes
2answers
155 views

Why do you have less control over a bicycle with a broader steer?

I recently had an argument with someone on why a bicycle with a broader steer gives you more control. We both had different answers to this question and neither could convince the other. First a ...
0
votes
1answer
40 views

Physics Forces and Friction [closed]

I'm working on this problem for my college physics class. It has to do with forces and friction and I want to make sure I go about this problem in the right way. I believe my teacher said that this is ...
6
votes
1answer
54 views

Physics behind the “Switch Pitch”?

I've come across this toy called a "Switch Pitch" designed by Chuck Hoberman. It's a ball that when tossed into the air (with some amount of rotation), inverts and changes colour. Made of plastic, ...
2
votes
1answer
42 views

How to find “Time” from “Force vs. Velocity” graph? [closed]

If I have Velocity on the $y$ axis and force on the $x$ axis how can I calculate the total time it takes to reach 4000 newtons? Is this just a case of integrating the gradient of the line?
0
votes
1answer
24 views

Finding Acceleration of Two Masses in an Ideal Pulley [closed]

I am stuck on this problem: Two masses are connected by a string which goes over an ideal pulley. Block A has a mass of 5kg and can slide along a rough plane inclined 30 degrees to the horizontal. ...
2
votes
0answers
31 views

Force and Energy in robots

There are two similar and hypothetical robots that move with wheels powered by motors, Robot A and Robot B. Robot A has a gear ratio of 3:1 (The gear connected to the motor is three times larger than ...
2
votes
1answer
42 views

How would the Sun's gravity affect us if we weren't in orbit?

So since we're in orbit around the sun, we are basically in free-fall. From what I understand, this means that we don't feel the gravity of the Sun like we do the Earth. Just like astronauts on the ...
24
votes
4answers
2k views

The physical definition of work seems paradoxical

So this is possibly a misunderstanding of the meaning of work, but all the Physics texts, sites, and wiki that I've read don't clear this up for me: In the simplest case with the simplest statement, ...
20
votes
5answers
4k views

Why are a motorcycle's front brakes more effective than back?

I've noticed that when I apply the front brakes on my bike it stops quite quickly. If I apply the back brakes at the same speed, it skids rather than stopping quickly. Why?
1
vote
1answer
83 views

Moment of inertia from torque and angular acceleration measurements

I tried to calculate the moment of inertia of a quadcopter along its roll axis using two different methods and the results do not match. Method 1: measuring the period of a bifilar pendulum, I obtain ...
0
votes
3answers
332 views

A simple logical problem regarding pressure and force

Suppose a 2 meter long pipe, with area of cross section is $1 m^2$. The pipe is vertically placed, with the bottom end closed. Inside the pipe, at the closed bottom end, there is $1 m^3$ of air, ...
4
votes
4answers
569 views

Why doesn't centrifugal force appear on an FBD for a car on a banked track?

Suppose you wish to find the max speed at which a car can travel on a banked curve of radius R and angle theta to the horizontal and coeff. of static friction mu. I don't understand the relevant ...
0
votes
1answer
46 views

The direction of frictional force in smooth rolling motion

I want to ask about the direction of frictional force in smooth rolling motion which means the rolling object doesn't slide on the surface. Here is the first case, the wheel rolls to the right so the ...
1
vote
3answers
64 views

Is linear momentum conserved in an isolated system always?

Consider a isolated system of particles. If no external force acts on this system, the momentum of the system should remain constant. If the isolated system of particles represents living ...
1
vote
1answer
61 views

Is energy affected by forces?

Curious, is any certain form of energy, such as heat, affected by a force? Can you push energy from one place to another?
1
vote
0answers
36 views

Force if a diver is lifting a pillar out of the water?(High school physics) [closed]

A diver is searching through the remains of an old shipwreck at a depth of 45 m below the surface of the ocean. The diver finds a marble pillar that is approximately 1.7 m x 0.15 m x 0.15 m in ...
0
votes
0answers
12 views

Reaction force due to the curvature and gradient drift

We know that a charged particle will have a drift velocity in both a curved magnetic field and when there is a transverse spatial gradient in the magnitude of the magnetic field. This drift velocity ...
0
votes
1answer
56 views

Centripetal force in loop motion

I saw it from the book which talk about centripetal force in circular motion The main idea here is the balance in the term of relation between velocity and centripetal acceleration - centripetal ...
2
votes
1answer
1k views

How is Mechanical advantage of Wedge = length of slope/width

Mechanical advantage is defined as Force Output/Force Input For a symmetrical wedge with the length of the slopes being equal and the width being the distance between the end points, articles quote ...
1
vote
1answer
87 views

Forces and motion (Newtonian)

A 10 kg monkey climbs up a massless rope that runs over a frictionless tree limb and back down to a 15 kg package on the ground. Part a) What is the magnitude of the least acceleration the monkey ...
3
votes
2answers
133 views

The force of gravity is $F_g=+mg$ or $F_g=-mg$?

I have noticed that in my classical mechanics course and in the textbook I read for it, seem to ignore the gravitational force's position. For example, if we were dealing with a system with a ball of ...
2
votes
2answers
218 views

How long does force apply?

If you were to throw a ball into the air while standing on earth, it will take some time to grow from zero relative velocity to it's maximum height before the velocity starts to increase again as its ...
1
vote
2answers
305 views

Does a heavy body move with the slightest force on a frictionless surface?

If I apply horizontal force on a body resting on the ground, my force will be opposed by the frictional force and the body will accelerate at the point where my force exceeds the force of friction = ...
2
votes
3answers
3k views

Why does rubber ball bounce back while iron ball doesn't?

Suppose there are two balls, one of rubber and the other metallic. There are of the same mass and are thrown on a wall with the same velocity. Why does a rubber ball bounce back while a metallic ball ...
0
votes
3answers
676 views

Question involving Vectors and Forces

This is a question I found in Mechanics for Engineers by Beer & Johnston. A 600-lb crate is supported by the rope and pulley arrangement as shown below. Write a computer program which can be ...
1
vote
1answer
42 views

Mass, Acceleration, and Force

The Problem: (a) A car of mass m is on an icy driveway inclined at an angle of 20$^{\circ}$, Determine the acceleration of the car, assuming that the incline is frictionless. The questions is ...
0
votes
1answer
230 views

A moving inclined plane with block problem

I'm trying to solve for a challenging problem : a moving inclined plane with a block I want to solve for the acceleration components for the block and the plane and the normal force acting on the ...
2
votes
2answers
32 views

The time interval of fundamental interactions?

I extract the below text snippet from our text book: Strong interaction is charge independent.The time interval of such a strong interaction is about $10^{-23} sec$ and it's range is approximately ...
0
votes
1answer
57 views

Gravitational force and Electromagnetic force?

I found this interesting note in one of my textbooks, The enormous strength of the electromagnetic force compared to gravity is evident in our daily life. When we hold a book in our hand, we are ...
0
votes
0answers
18 views

Does a pebble create a double torus when hitting water

If you watch slow motion vids of a water droplet or stone hitting water you notice some comes back up. Is this due to some double torus action? There is displacement and some bounce back from the ...
-2
votes
1answer
70 views

Is there always motion, when force is present? Is all motion vibration?

Even when you are seated in a chair, the chair is pushing up on you and you down on the chair (manifesting in the form of ~650N). While there is no obvious observable motion, is it not possible that ...
1
vote
2answers
131 views

Tension of rope. Different Answers?

The tension of a rope in a tug of war with unequal forces is equal to the least force on the rope. Am I right? (If group A pulls the wire with 20 newton leftwards and the group B pulls with 30 newton. ...
0
votes
1answer
53 views

Gravitational work

As far as I know gravitational work is independent from the path of the object, and I have an object that goes up on a inclined plane to a certain height, and than, after the object reaches the edge ...
5
votes
1answer
145 views

Force problem related to adhesive and bonding

I have two PCBs (printed circuit board), and they are glued by adhesives, as show in the pictures. And the location of the adhesives are indicated on the picture (please notice that NO adhesive is ...
0
votes
3answers
133 views

Force vs. impulse: what is the math description of their interaction?

Suppose the box (stone, bullet..., $m =1$) is not moving upward because of a lift, but has been shot and has $p = 20 kgm/s, v = 20m/s, KE = 200 J$ Gravity is doing negative work and subtracting ...
0
votes
1answer
54 views

Calculating the acceleration in a multiple pulley system with one mass? [closed]

This sounded really simple to me at first, but how would you calculate acceleration within a multiple pulley system like this one . I understand that $5T = mg \implies T = \frac{mg}{5}$, but what if ...
0
votes
2answers
50 views

Work and Free Body Diagrams

I am a bit confused with how to find work when there is a free body diagram. I am trying to work out this problem, and in it a box is being pulled at a constant speed by a rope at a constant angle ...
1
vote
1answer
80 views

Langevin equations in translational and rotational direction

I want to describe the following system. A bead is connected with a tether. There is a force $\vec{F}_{up}=F_{up}\hat{y}$ that acts on the bead. The tether acts with a force on the bead, this force ...
0
votes
2answers
548 views

Different directions of frictional force when objects are rolling

My textbook has two instances of rolling bodies (smooth rolling). In the first, the body is rolling on the horizontal floor with some acceleration of its centre of mass. In this case, the book says ...
0
votes
2answers
70 views

Definition of torque for a continuous body

I am working on basic physics definitions. Given a particle at position $r$ (in some coorinate reference system) upon which acts a force $F$, the $torque$ $\tau$ is defined by \begin{equation} ...
2
votes
1answer
170 views

Large deflection of cantilever beam

How can I find the amount of point force at the end of a cantilever plastic beam that produces e.g. 45deg slop at the end of the beam? Is this the right equation: $$F=\frac{2EI\theta ^2}{L^2 ...
1
vote
3answers
258 views

Confused about Newton's 3rd law

I am confused about Newton's 3rd Law. If a person jumps off the ground a force is applied both to the person and to the ground. However, as $F=ma$ acceleration experienced by the Earth is much less ...
2
votes
1answer
77 views

How to calculate the force acting on a magnet due to a solenoid

Can I assume both magnet and solenoid as magnetic dipole and use Coulombs law to find the force acting the magnet?