Newtonian mechanics covers the discussion of the movement of classical bodies under the influence of forces by making use of Newton’s three laws. For more general discussion of energy, momentum conservation etc., use classical-mechanics, for Newton’s description of gravity, use newtonian-gravity.

learn more… | top users | synonyms (2)

4
votes
1answer
65 views

Faster than critical damping for harmonic oscillator?

The image below shows damping for spring oscillator with Hooke law F=-kx and damped with F=-cv where: k is spring constant x is oscillator position c is damping coefficient v is velocity of oscillator ...
19
votes
9answers
6k views

Why is torque not measured in Joules?

Recently, I was doing my homework and I found out that Torque can be calculated using $\tau = rF$. This means the units of torque are Newton meters. Energy is also measured in Newton meters which are ...
7
votes
1answer
467 views

Camp Fire Crackle

I was sitting around the camp fire and there was a periodic sound of cracking and pieces of the burning wood flew off. My question is what is the mechanism for the cracking of the wood? I was thinking ...
1
vote
0answers
34 views

How does a simple weighing balance actually work? [duplicate]

I have made a simple sketch of how I think the system looks like. My problem is: I always thought that the angle the balance makes is a function of the difference between the two masses (or the ...
0
votes
1answer
55 views

Friction influencing the motion of a mass and non-inertial frame of reference [closed]

So... recently a Newtonian-mechanics related exercise has raised in me many questions basically ragarding which forces influence a given system and how, I know they might sound bit too "noobish" but I ...
0
votes
1answer
18 views

Do I need the exact velocity when experimenting with sliding coins?

I'm doing a home experiment but it's not going very well. I'm pushing coins on a table. I'm taking the time for how long it takes coin A to hit coin B and then I divide it by the time between them ...
0
votes
0answers
34 views

Classical rod-wall-floor system

I have a homogeneous thin rod $AB$. $A$ can slide along $z$-axis, $B$ along $xy$ plane. There is no friction. We have any initial conditions. Now the question is to write down the equation of motion ...
1
vote
0answers
15 views

Calculating rate of change of momentum for a package [closed]

A helicopter is flying to the right (in the $+x$ direction) with a constant speed $v$, carrying a package of mass $M$ suspended below it using a cable as shown in the figure. (You can assume that $H$ ...
2
votes
1answer
202 views

The Relationship Between Crater Diameter and the Velocity of an Object

I'm doing a design lab, where I have to "investigate the nature of craters formed on sand." I've done some research and figured out that the cube of the diameter ($d$) of the crater formed by an ...
1
vote
0answers
34 views

Finding gravitational potential due to ring [closed]

A point P lies on the axis of a fixed ring of mass M and radius R at a distance of 2R from its centre O. A small particle starts from P and reaches O under gravitational attraction only.its speed at O ...
1
vote
1answer
29 views

How far do atoms move in a wire when whirling it horizontally?

so the question is: I whirl a mass m attached to a wire with length L and diameter d around my head in the horizontal plane. The mass takes t seconds to move around a circle. How far do the ...
0
votes
1answer
30 views

Finding a 1-Dimensional Mass Distribution

Past Discussion There have been a lot of questions and discussions regarding determining the mass distribution of various bodies through non-destructive purposes. Here are a few: Determination of ...
-1
votes
1answer
29 views

A block falling from a height on a block suspended by spring [closed]

The block suspended by the spring is hanging freely and its mass is M. The small block of mass m is dropped on the bigger block from height h. After the small block is dropped 》》》 I want help in ...
2
votes
1answer
634 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 ...
3
votes
2answers
46 views

Taking pivot about an accelerating point

Given this question: A small ball of mass $m$ and radius $r$ rolls without slipping on the inside surface of a fixed hemispherical bowl of radius $R>r$. What is the frequency of small ...
0
votes
1answer
61 views

Integrating for speed [closed]

Trying to determine the speed of a falling body with respect to traveled distance and initial speed. I've been provided with the following equation for acceleration as a function of distance and the ...
4
votes
1answer
144 views

Does total angular momentum of the Earth-Moon system include individual rotational angular momenta?

To calculate the angular momentum of a body we need to specify a point (or an axis?) from which to define the displacement vector $\vec{r}$, so that $\vec{L} = \vec{r} \times \vec{p}$. For a rigid ...
12
votes
0answers
131 views

How fast would a truck have to go to pull a pedestrian onto the road?

Let's suppose a pedestrian P is walking or standing next to a highway. Suppose a truck T will drive by the said pedestrian at speed V leaving distance L between the two. How fast would the truck have ...
1
vote
2answers
66 views

How much force is required to compress air?

How much force (Newtons) is required to compress normal air in a chamber to 2 atm? For example, if I had a sealed piston pump, how much force would need to be exerted in order for the air to be ...
3
votes
1answer
332 views

Two vehicles moving in a line with different accelerations

Let two similar vehicles starting at rest in a straight line (with a distance of $D$ between them) have time-varying accelerations in the same direction. If both of them have similar time varying ...
2
votes
4answers
92 views

Deriving $F = ma$ - Newton's Second Law of Motion

Context: In my textbook it is given: 'momentum' short for 'linear momentum': Mass = $m$, momentum is $p=mv$. In time $\Delta t$, momentum changes by $\Delta p$, the rate of change of momentum is: ...
0
votes
1answer
95 views

How do I correctly choose signs for a falling particle?

An object falls from a height $h$ above water through air with negligible drag. In the water, the upward buoyancy exactly balances the downward gravitation force. The only remaining force on the ...
1
vote
3answers
152 views

Effect of incoming force on linear vs. angular velocity

First of all, I should note that I'm a programmer and have only an extremely basic understanding of physics; I only know how to explain my question in layman's terms and I apologize if I'm unclear or ...
10
votes
7answers
2k views

Does leaning (banking) help cause turning on a bicycle?

I think it's clear enough that if you turn your bicycle's steering wheel left, while moving, and you don't lean left, the bike will fall over (to the right) as you turn. I figure this is because the ...
0
votes
2answers
130 views

Difference between the two equations for acceleration

I came upon this while studying S.H.M. Well,is there a difference between writing $$a=\frac{dv}{dt}\;$$ and $$a=v\frac{dv}{dx}\;$$ do they differ on the basis of one being a vector and the other ...
2
votes
1answer
52 views

Why are non-horizontal levers not considered to be in equilibrium?

Consider a triple-beam balance, like so: An unknown mass is placed on the left pan, and the provided weights are moved on the right until the lever arm comes to rest at an exactly horizontal ...
0
votes
1answer
56 views

Lagrangian for a moving spring device

How can I write the proper Lagrangian for such as system as the one shown in picture? Am confused about what is the suitable way to designate the coordinate.
1
vote
1answer
57 views

How quickly does air return to a vacuum chamber?

I know there are a lot of variables that affect how quickly this would occur. Any information on the topic would be highly appreciated. For sake of argument, lets say 1 square foot chamber, lets say ...
1
vote
1answer
48 views

Confused with how to approach this pulley problem (solved) [closed]

Question: In the following figure block A has mass m and block B has mass 6.00. The coefficient of kinetic friction between block A and the tabletop is 0.40 The mass of the rope connecting the blocks ...
0
votes
1answer
125 views

Block Sliding Down a Plane (Perpendicular Velocity)

I'm having trouble understand the concepts for this problem. Here's the problem: A block is placed on a plane inclined at angle $\theta$. The coefficient of friction between the block and the ...
6
votes
10answers
282 views

Why is centrifugal 'force' perpendicular to line of inertia

I know that centrifugal is labeled a fictitious force only arising in a rotating reference frame, but I still struggle to understand the forces at play intuitively in tethered rotating bodies. I've ...
1
vote
1answer
52 views

Max altitude of rocket [closed]

A rocket is launched perpendicularly with an initial acceleration of 10 m/s2, if the fuel runs out after 1 minute, what will be the maximum height reached by the rocket?
-2
votes
0answers
26 views

simple pendulum rotating in a horizontal plane [duplicate]

imagine you are rotating a simple pendulum above your head in a horizontal plane. is it possible to keep the pendulum in the horizontal plane. if yes, i want to know what is the force that keeps ...
1
vote
1answer
35 views

Is there no problem in thinking of any motion of a rigid body as a composition of translational motion and rotation w.r.t center of mass?

Sometimes when I work on mechanics problems, I wonder if this analysis is always valid. Couldn't there be some motion of a rigid body that cannot be expressed as a composition of translational ...
7
votes
1answer
362 views

What will be different if the spring is not massless?

In almost all text, it uses the massless spring as example to illustrate the idea of elastic potential energy. I wonder what's really being changed if we consider the mass of the spring? I saw a ...
0
votes
2answers
69 views

Problem with horizontal projectile motion questions

I don't really understand horizontal projectile motion. Suppose I throw a ball horizontally. Given $\theta$ = 0 degrees, time = 0.5 seconds, horizontal range = 15.5 metres, the "initial horizontal ...
2
votes
7answers
483 views

Metallic and glass sphere of same size released at a height

This question was in my exam today : A metallic and glass sphere of same size were dropped at same height. Which sphere would hit the ground first and why? I have thought about several things and ...
0
votes
0answers
21 views

Question about two masses connected by a spring [duplicate]

I have two masses connected by a spring. They are horizontal and are not affected by friction or gravity. The spring's stiffness constant is $k$, and $x_1$ and $x_2$ are the displacements of the ...
0
votes
0answers
63 views

More on the closed-form for a simple pendulum

I've learnt about the simple pendulum, and while the regular curriculum only uses the linear approximation of $\sin\theta$ to obtain $\ddot\theta+\omega_0^{2}\theta=0$. I tried to find out about a ...
3
votes
2answers
3k views

Analyzing the motion of a ball rolling without slipping inside a hemispherical bowl

Consider a solid ball of radius $r$ and mass $m$ rolling without slipping in a hemispherical bowl of radius $R$ (simple back and forth motion). Now, I assume the oscillations are small and so the ...
0
votes
0answers
52 views

Calculating Inertia Tensor with Parallel Axis Theorem

Say you have a solid you are approximating as n point masses at different points in a 3D space. Each point mass has a mass of 1. The origin is not the center of mass. All the points have location ...
1
vote
0answers
42 views

Block on block with friction [closed]

I couldn't find a similar question here - I'm guessing because it's kind of elementary. Lets say we have two blocks, $B_1$ and $B_2$, of mass $m_1$ and $m_2$ (respectively), where $B_1$ is directly ...
2
votes
2answers
45 views

Acceleration of chairlift [closed]

So I'm struggling with this question, and am wondering if anyone can give me the right direction to go. For the sake of not cheating, I've changed the figures etc. I just need help on the approach. I ...
0
votes
0answers
16 views

friction on a solid body due to another solid body

Suppose we have a block A and is moving on a rough horizontal surface with a velocity 60 m/s and another block B of same mass moving with velocity 5 m/s on same horizontal surface and suppose they ...
0
votes
0answers
23 views

An easy source to understand classical dynamics — Rigid body Rotation [duplicate]

I've been having an extremely hard time at understanding rigid body rotation. The source that I'm currently studying from has been suggested by 't Hooft on his webpage. It's by Richard Fitzpatrick. ...
5
votes
4answers
694 views

Explaining Newton's Laws of motion to a 6 year old

An old professor of mine once said that an effective means to get people interested in Physics is to get them started early. What would be an effective and meaningful (and fun) means to explain ...
0
votes
1answer
40 views

What forces are involved in this situation?

A old massless rope of 12 meters attached to a ceiling can sustain a maximum tension force of 1200N before breaking. An 85 kg person climbs up the rope. What is the minimum possible time in which ...
0
votes
0answers
51 views

Free fall from space [duplicate]

If you leave a ball weighing 10 kg at a height of 500 km above sea level (neglecting air friction). How can calculate how long the ball hits the ground and what will be its speed? I know that: On ...
1
vote
2answers
93 views

Determining the direction of friction

I had a question which has always been of slight confusion to me. Say you are dealing with your typical block-on-an-angled-plane setup. You have a block with mass m that is initially at rest. The ...
1
vote
1answer
54 views

Conservation of energy quick question

Say we had a particle moving in a frictionless funnel and was projected horizontally. If we had some initial conditions for the energy E, then would these conditions be the same always? For ...