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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Impact force on a Full Suspension Mountain Bike

I have a full suspension MTB design and i will do a structural analysis using a FEA tool.For this purpose,i have to calculate the forces applied on both wheels when the bike falls from a certain ...
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2answers
66 views

What force needs to be applied to produce twice as much acceleration as already present in a body?

Let the current body of mass $m$ be moving with acceleration $a$, produced by applying $F = ma$. So, I thought that if I apply force $F$ again (same magnitude and direction as before), I would get ...
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0answers
24 views

Why friction increases with increase in normal force? [duplicate]

Why is friction dependent on normal force and not the actual weight? I have also read that friction is horizontal component of contact force. Is this true?
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1answer
24 views

Central Force - Trajectory [on hold]

There is a central force $\vec{F}(\vec{r})=f(r)\vec{e_r}$. 1.1.: The trajectory/flight path is defined by $r=r(\phi)$, compute $f(r)$. 1.2.: The path is defined by $u=u(\phi)$ with ...
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0answers
28 views

Central Force - Trajectory [duplicate]

There is a central force $\vec{F}(\vec{r})=f(r)\vec{e_r}$. 1.1.: The trajectory/flight path is defined by $r=r(\phi)$, compute $f(r)$. 1.2.: The path is defined by $u=u(\phi)$ with ...
2
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1answer
28 views

Force needed to roll wheel over edge [on hold]

I'm looking to find F. See image below. What we know: Mass of the wheel: $ m = 14 $ kg Wheel radius: $ r = 0.32 $ m What I've tried so far: $$ mg + N + \sin(38.7)k = 0 $$ Once the wheel ...
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0answers
17 views

Force acting on a wheel of a two-wheeled self balancing bot

Proceeding further with my work on a self-balancing bot as posted here: http://bit.ly/1FfI6LK I've gotten stuck at the following equation: n = Gear ratio $K_t$ = DC motor torque constant $i_l$ = DC ...
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1answer
31 views

Finding the tension in a rope with mass defined per unit length [on hold]

A rope of length L has its mass per unit length λ varies according to the function λ(x)=e^x/L. The rope is pulled by a constant force of 1N on a smooth horizontal surface. Find tension in the rope at ...
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1answer
38 views

Relativistic Lorentz Force with constant, perpendiuclar, and uniform E and B fields

I am trying to solve the following problem from the Fundamentals of Plasma Physics by Bittencourt (Problem 2.7): Analyze the motion of a relativistic charged particle in the presence of crossed ...
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0answers
30 views

Can a magnetic field be expelled over long arbitrary distances through a super conductor? [on hold]

I'm not a physiscist but i have a creative concept I wish to make into a environmental commercial before my Interactive Feature Film. Apologies, if it sounds like I have no idea what I'm talking ...
3
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1answer
104 views

Is it possible to apply force to a light particle?

I know, the universal speed limit is the speed of light $c$. So, is it possible to apply more force to a light particle? What would happen to it if we could?
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2answers
43 views

Static friction and Kinetic friction

I can't seem to find this anywhere on the internet or on stack... Sadly. Very basic question: I have a block that is on a surface. The coefficient of static friction between the two is $0.3$, ...
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0answers
61 views

Why Does Moving a Cup of Coffee Up and Down whilst carrying it Make it less Likely to Spill?

Sometimes I have a Very Full Mug of Coffee and I am trying to carry it without it spilling. I noticed that if I moved the Mug up and down when carrying it, it seemed to settle the coffee and make it ...
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0answers
19 views

Find direction and magnitude of net electrostatic force on a point charge [on hold]

Question: Find the direction and magnitude of the net electrostatic force exerted on the point charge $q_2$. Let $q = +2.4μC$ and $d = 33cm$. What I tried: I used the formula $F = kq_1q_2/d^2$ to ...
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0answers
22 views

Finding displacement of spring [closed]

Q) A block lies on a horizontal frictionless surface, and the spring constant is $50\,\mathrm{N/m}$. Initially, the spring is at its relaxed length and the block is stationary at position $x=0$. ...
0
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0answers
29 views

The minimum force required to lift a triangular prism [on hold]

If I have an isosceles triangular prism of mass m with the angle at the top being $2\theta$ I want to work out the minimum force I would need to apply to the upper faces to lift the prism. Lets say ...
4
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5answers
228 views

$F=ma$, so if acceleration is zero the force must also be zero?

I was just pushing a huge rock which I couldn't move at all. Given that the acceleration was zero as a result of my efforts, since $F=ma$, doesn't this mean that the force must also have been zero? ...
3
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1answer
127 views

What are the proposed theoretical explanations for the EmDrive?

The EmDrive is a proposed propulsion mechanism for spacecraft in which some form of microwave device provides the propulsion. The consensus from the physics community, including many voices on this ...
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4answers
134 views
2
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2answers
45 views

How can tangential acceleration from a radial force be explained?

A mass is attached to a rope, and put into a circular motion. If I pull the string from the center, the tangential speed of the mass will increase (by conservation of angular momentum). I am ...
1
vote
1answer
39 views

Maximum angle for highway lane change

I am preparing to fight a traffic ticket from a speed camera. There is a lot more to that story, but the info I need right now involves the angle at which a car can change lanes, in terms of vehicle ...
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3answers
99 views

Can two electrons attract each other?

Due to electrostatic repulsion the two electrons will repel each other as they both possess similar charges, lets leave gravitational attractive force out of the picture my question is can there be ...
1
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0answers
30 views

Potential (which only depends on the length of a position vector) [closed]

a) A potential $U$ only depends on the length $r=|\vec{r}|$ of the position vector $r$. Show that $$\vec{\nabla}U(r)=U'(r)\frac{\vec{r}}{r}. $$ What properties does this vector field have? ...
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1answer
28 views

Friction on a body

Consider a cuboidal block kept on a table with friction coefficient $\mu$. When calculating the friction, we use $f= \mu n$ where $n=mg$ for a horizontal table. But a pressure due to the atmosphere ...
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2answers
37 views

In which direction does mud fly off a moving bike's tire & why?

If a bike moves through a muddy area, mud gets on its tires. Then the mud flies off from the tires. Which forces are acting on it? In which direction does it fly off? On my physics test, I wrote ...
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1answer
26 views

How would change force of gravity? [closed]

How would change force of gravity, impacting some object, when this object is lifted on height $h = 3 \cdot R_3$. The right answer stated as ("decrease 16 times"). I want to know why.
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1answer
10 views

Is the index of time in the unit equivalent to force dependent on the number of dimensions

When the unit of force is represented as $\text{distance per time}^n$ in 3 dimensions $n$ is equal to 2. Is n also equal to 2 for higher or lower dimensions (2D, 4D, 5D, ...) or is it dependent on the ...
4
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3answers
623 views

Work = Force x Distance vs Displacement

The difference in using Distance vs Displacement is demonstrated in this example: Work = Force x Distance If I carry an object to and fro 10 metres, the work done would be Force x 20 metres. ...
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votes
3answers
52 views

Question on normal force and static friction [closed]

Why is this statement false: If the normal force on an object increases, the static friction must increase? Thank you! Is it because they did not state what normal force is referring to?
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0answers
14 views

How this tube rotates? [duplicate]

I recently seen a video where a tube is spin into space. When it starts to rotate, it keeps continuously to rotate along the axis of 180 degrees clockwise, then 180 counter-clockwise and so on. The ...
2
votes
3answers
364 views

Why do non-accelerating objects exert force on each other?

The equation for force is $\vec{F} = m\vec{a}$, where $\vec{a}$ is acceleration. Acceleration is a change in velocity. However, if an object with constant velocity (i.e. 0 acceleration) hits another ...
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2answers
47 views

simple force question

So given this diagram, I was supposed to find the magnitude and direction of the net force on the -10nC charge on the bottom right corner. I found the magnitude by myself using Coulomb's law for the ...
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1answer
68 views

Do we all actually just weigh half of what our bathroom scales tell us?

Here's the reasoning: Newton's third law tells us that every force has an equal but opposite reaction force. So besides my weight pushing down on the scale from above, there's also an equal force ...
2
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2answers
75 views

Mathematical Proof of Force

I remembered reading an paper a while ago which tried to prove whether force actually exists, or if it a man made construct to aid our understanding of the world. However, I can't seem to find the ...
1
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1answer
45 views

How does one calculate or even approximate the force observed by a magnet as its dropped inside of a diamagnetic cylinder?

How does one calculate or even approximate the force observed by a magnet as its dropped inside of a diamagnetic cylinder? Wikipedia and Google does not provide much information on this topic. ...
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2answers
37 views

Can we make a force which can oppose earth gravity? [duplicate]

IF We are standing on a earth.then some force (gravity of earth) is pulling us down..then "cant we make a force which can oppose gravity..? Cant we make a object of zero mass..?
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2answers
30 views

frictional force is nonconservative force [duplicate]

In nature there are mainly four kind of fundamental forces,electromagnetic force is one of them which is conservative force.If friction force is belongs to electromagnetic force then why it is not ...
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2answers
74 views

Gravitational force in a building

Suppose that a person is standing on the top of a multi storey building and at an instant earth's gravitational pull becomes zero.What will happen in the next instant? (Consider only earth's gravity ...
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0answers
9 views

What angle - for a strut - provides the greatest vertical strength/support for cantilever [duplicate]

What angle - for a strut - provides the greatest vertical strength/support, for the free end of a cantilever
1
vote
1answer
23 views

Half of a uniform disc suspended by two strings [closed]

Suppose we have a half of a thin, homogenous disc hanging from the ceiling as shown: Given the weight of the disc $Q$, calculate tensions in strings $S_1$,$S_2$. Now this seemed like quite a simple ...
2
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0answers
22 views

Force required to crop/cut a mild steel bar [closed]

I have cropping wedges with a diameter of 4mm cutting either side of a round mild steel bar (17.5mm). These wedges are operated using 2 hydraulic cylinders (6" diameter, 2 1/2 travel) (one for each ...
0
votes
1answer
28 views

Coefficient of elasticity of the spring?

I know this might sound a silly question though For a spring that is compressed lets say x meters by a force F N. what is coefficient of elasticity of the spring? We are not given the equilibrium ...
2
votes
3answers
140 views

Weight distributions [duplicate]

If a man is standing on two weighing machines (scales), with one foot on each, Will both machines show equal weight or his weight will be distributed in two machines?
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0answers
20 views

How is the strength of a force quantitatively evaluated?

Physicists often talk about the 'strength' of a force. For example, gravity is weak, the strong force is of course strong. The hierarchy is summarized on this wikipedia page, which lists strengths in ...
0
votes
1answer
45 views

Maximum range of projectile launched from an inclined plane [closed]

As we already know the max range if we launch it from any flat surface or from any height but I was wondering what will be maximum range if we launch it from inclined plane. I have made on figure of ...
1
vote
2answers
73 views

Why do we feel resistance to gravity rather than the acceleration of gravity?

What's the reason it behaves differently from all other forces? What I mean is, if you're in orbit you're accelerating toward the earth at almost 9.8m/s^2, but you feel nothing. If you are riding a ...
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0answers
14 views

Determining length of slope from angle and time down slope

I'm aware this is probably trivial, but I'm having a hard time with the following problem: "A child on a sled starts from rest at the top of a 15° slope. If the trip to the bottom takes 15.5 s how ...
0
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1answer
38 views

Force in a moving object that is not accelerating

If an object is traveling in a straight direction at a constant speed it has no acceleration, right? So if $F=ma$ and $a =0$ then force should equal 0. Does that mean a car traveling at a constant ...
2
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2answers
35 views

Does friction act on a wheel rolling at a constant speed

One of the things I've seemed to have taken for granted is that its the friction the floor exerts on a rolling wheel that prevents slip from occurring. However, I ran into something that challenges ...
0
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1answer
26 views

What does “interact via strong force” mean?

I was just wondering if the words "strong force" and "strong interaction" are interchangeable? Also, these are referring to "strong nuclear force", correct? Then what does it mean for particles to ...