Stack Exchange Network

Stack Exchange network consists of 175 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

Questions tagged [newtonian-mechanics]

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.

0
votes
1answer
35 views

When water flows over a curved surface, will it reduce the pressure on the curved surface? Is this because of the viscosity of water?

I think it's because water moves on a curved surface with centripetal force. Because the gravity of water provides centripetal force, the pressure of water on the curved surface is reduced. When the ...
-1
votes
1answer
48 views

How does velocity being given to the bob here create tension in the string? [closed]

Based on intuition, the lesser the velocity the bob is initially given, the sooner will the string slack. I don’t understand how the velocity the bob is given initially is related to tension being ...
4
votes
1answer
84 views

What should be the speed of my bullet be to punch a nice round hole through a paper sheet?

If my bullet travels faster will the amount of damage done to the paper be lesser? Due to inertia of the paper can the bullet make bullet shaped holes instead of making a big hole as the speed ...
1
vote
1answer
104 views

Are there 2 laws of motion or only 1?

It seems clear that Newton's first law is a special case of his second. Although perhaps people might argue that it emphasizes the centrality of inertial frames. But is the third law also just a ...
2
votes
4answers
123 views

Can we do a thought experiment to prove that the horizontal and vertical motion of a projectile are independent of each other?

It seems really hard for me to grasp the idea that horizontal and vertical motion of a projectile are independent of each other. Intuitively I feel that they should affect each other. How can it be ...
2
votes
2answers
44 views

Do faster moving projectiles make larger penetration holes? [closed]

When it comes to shooting guns, a bullet of a certain size will make a certain size hole in the paper or wood target. A $.22$ bullet makes a pea size hole regardless of if its shot out of a pistol ...
0
votes
2answers
70 views

Revolution of Earth around the Sun

We study the orbit of many planets around the sun modelling it as a uniform circular motion. Is this due to the fact that empirically we measured that the magnitude of the earth's velocity (for ...
-1
votes
4answers
94 views

Newtonian mechanics. If I'm inside a wagon and I pull a spring connected to the wall, will the wagon move? [closed]

Suppose the mass of the wagon is very small. There's a spring connected to the wall inside the wagon. If I pull the spring, does the wagon move?
0
votes
4answers
52 views

A rod rotating about a pivot

A long, uniform rod of length L and mass M is pivoted about a frictionless, horizontal pin through one end. The rod is nudged from rest in a vertical position as shown in figure. At the instant the ...
1
vote
1answer
71 views

What happens when in space a basketball flies and hits another resting basketball?

We have the following situation: In space, a basketball flies and hits another resting basketball. What happens next? a) Both balls fly in the original direction (but slightly slower) = momentum ...
0
votes
2answers
61 views

Gravitation in relativity vs classical physics and the 1919 eclipse experiment

I am trying to understand the issue of light bending in relativity vs classical physics. I will clearly describe my understanding/assumptions in case I am wrong on those. In relativity, unlike ...
0
votes
1answer
55 views

Gravitational force in a lever [closed]

Let's consider a lever with some objects on it. The objects have the same mass. We know that an equal gravitational force acts on the objects. Its formula is: $\bar{F}=m\frac{d\bar{v}}{dt}$ This ...
0
votes
1answer
59 views

Why is energy exponential with respect to the force impulses required to achieve those energies? [closed]

I'm looking for a simple and or profound answer to my question. If you propel a kilogram to 10 meters per second, you have an energy of 50 joules. If you triple that force impulse and propel a ...
1
vote
1answer
24 views

Can I calculate tension in a preloaded string by superposition when the string is deformed?

I am trying to calculate the tension in a string with preloaded tension after a force is applied to the string as in the diagram below. The string would be under tension prior to the force $F$ being ...
0
votes
1answer
22 views

Finding acceleration of a stacked box system, when they are not relative [closed]

Two boxes are stacked, box $A$ is placed on a horizontal surface with no friction, box $B$ is placed on box $A$ with unknown coefficient friction between the two. Box $A$ does not slide relative to ...
10
votes
6answers
2k views

How exactly does artificial gravity work?

A spaceship which uses centripetal rotation to create artificial gravity. Must it always be accelerating? (The rate of rotation for it to work?) If no, and even if yes, if one were to place ...
5
votes
3answers
190 views

Definition of Newton's first law [duplicate]

I have always had a doubt in the definition of the Newton's first law. In general, it is stated in a form like: An object at rest remains at rest, or if in motion, remains in motion at a constant ...
2
votes
1answer
41 views

Friction in pulleys

The moment equation of a pulley with a rope applying tension on both sides is as follows: $$I\alpha = f + T_1R - T_2R$$ ( $I$ - moment of inertia; $\alpha$ - angular acceleration; $f$ - friction ...
1
vote
1answer
35 views

How can a rope's tension be at a maximum as a body is about to move up a slope in the rope's direction? [closed]

Note: I do NOT need this exercise's answer. I have no problem working the math out and noticing the truth of my title. A box of mass 0.5 kg is placed on a plane which is inclined at an angle of 40 ...
0
votes
3answers
40 views

Normal force at each support for a stick with two supports

This is a physics/mathematical modeling problem I gave myself and I got kind of stuck here trying to model it. Imagine having some kind of stick or cane (don't assume uniform density) and supporting ...
1
vote
3answers
65 views

How to measure mass using centripetal force?

I was just reading through Volume I, Chapter $9$ of the Feynman Lectures, where he's discussing Newton's dynamics. He says, We use the term mass as a quantitative measure of inertia, and we may ...
1
vote
0answers
47 views

A query on Newton's second law [duplicate]

Upon studying Newton's second law, I noticed that it seems less of a physical law i.e. outcome of some experiment, than something we built upon how WE define mass and force. The ratio of the masses $...
0
votes
1answer
72 views

Confusion on this Vector Problem

I found this question online and gave it a try, it seemed simple but I keep getting the wrong answer. One way or another my calculation keep showing me the answer B, which is regarded false. The ...
0
votes
0answers
16 views

Waves velocity for a standing wave of a string

I have done a laboratory experience to determine the speed of propagation of a wave in a vibrating magnetic string. To calculate the frequency (f) of oscillation I used an oscilloscope that calculated ...
0
votes
0answers
18 views

Will a cantilever tube vibrate if fluid enters from its free end and flows into the fixed end?

For dynamics of a cantilever pipe with fluid flowing from fixed end towards free end, there are values of frequency for a threshold of flow velocity that gives unstable, stable and neutral systems, ...
0
votes
1answer
20 views

Work done and change in mechanical energy

I have a hard time understanding the equation $W_{Driving} +W_{Friction} = \Delta E_{mechanical}$ Is there any derivation of it?
1
vote
1answer
53 views

Given that the Moon affects tides and most of the human body is water, do tides affect people?

It is known that the Moon causes tides. Given that the human body is 60%-70% water, is there any research that shows that the tides affect humans in any tangible way? If this is not the appropriate ...
16
votes
7answers
5k views

Why does the Earth follow an elliptical trajectory rather than a parabolic one?

I was taught that when the acceleration experienced by a body is constant, that body follows a parabolic curve. This seems logical because constant acceleration means velocity that is linear and ...
-1
votes
1answer
41 views

Centre of mass location

How and why is com affected when an EXTERNAL force is is applied ? What forces do we consider internal ? Please provide some visual examples Like men walking on plank, wedge mass system.
0
votes
1answer
35 views

Question about Normal/Tangential coordinates

I have been told that position is a vector. It goes from the origin to the object that is moving. If that vector is a function of time, its first derivative gives the velocity vector and its second ...
0
votes
2answers
39 views

Applying external force on test charge greater than repulsive force of electric field

In the textbook, it is written that only that amount of external force is applied that balances the repulsive force of the electric field without producing acceleration. Without acceleration, is it ...
0
votes
0answers
22 views

Dynamics Circular Motion

For circular motion to occur a centripetal force is required, in the case of a bicycle when turning; the where does the centripetal force come from since the force of friction is not great enough and ...
0
votes
1answer
46 views

What's the maximum compression of the spring? [closed]

I tried to use the conservation of energy to solve this problem, here's what I tried to do: $\require{enclose}$ $$\begin{align} \enclose{downdiagonalstrike} {\frac{1}{2}} m v^{2} &= \enclose{...
0
votes
2answers
69 views

How do I write the equation of motion for a pulley on a fixed rope? [closed]

I've got complex dynamics problem I'm trying to solve, but the crux of my problem at the moment is describing the path a pulley would take on a rope of fixed length. Assume the rope is fixed at ...
0
votes
0answers
34 views

Spaceship artificial gravity synchronization

Probably you remember the scene from "2001, Space Odyssey", where a small shuttle flies to low Earth orbit to reach a giant, ring-shaped mothership that rotates to generate artificial gravity, while ...
1
vote
3answers
85 views

How is final velocity negative when acceleration is in positive direction?

When a body starts from rest and starts accelerating in positive direction and moves certain positive distance, its final velocity is given by : $$v^2 = u^2 + 2as$$ Solving it gives two values of $v$, ...
0
votes
0answers
53 views

Why don't we define time derivative of acceleration? [duplicate]

When we started the study of kinematics we defined position and its change with respect to time. After that we defined time derivative of velocity which gave us acceleration. These 3 concepts really ...
0
votes
1answer
37 views

How to measure the mechanical vibration when a hammer hits a nail? [closed]

I want to know the exact location of the vibration sensor that can be placed to measure the vibrations created by a hammer hits the nail.
0
votes
1answer
39 views

Modeling the distance between two point masses in space with gravity as a function of time

Assume that there exist two point masses in space, an isolated system with only gravity acting. I wish to find the distance between the masses as a function of time. I have arrived at the result of $$...
0
votes
1answer
34 views

Finding speed in the system

This a quite simple question, unfortunately I can't get why my solution and the correct solution don't match. A particle P of mass $0.2$ kg rests on a rough plane inclined at $30$ degrees to the ...
1
vote
0answers
64 views

Problem with Impure Rolling [closed]

Can someone explain what happens in the below situation Looking at it from the planks frame of reference: The cylinder Velocity= 20(-i) Net friction force on cylinder f=2umg(i) (here u=1/2) ...
2
votes
0answers
32 views

Deriving the lever law using infinitesimals

I'm trying to derive the lever law by myself, however, I'm stuck. Please follow the logic of my calculations. Every object in the picture has the same mass. I want to prove that, under the effect of ...
2
votes
2answers
57 views

How do you find the minimum height to open a parachute for a safe landing?

What concepts/formulas can be used to find the optimum/minimum release height of a parachute?
0
votes
1answer
19 views

Sense of Coriolis force and Tractive force

I was solving a problem in Mechanics of material point and a part required to calculate the coriolis and tractive forces. So in the solution of this problem I realized that my answer missed the fact ...
0
votes
1answer
23 views

Net Force regarding Impulse and Momentum

I'm just going to preface this with: I don't know much, I've just started learning about impulse. Question: If there is a change in velocity regarding momentum $P$ then would there be a net force on ...
2
votes
4answers
119 views

Why is the work done by tension in a pulley always zero?

Consider a pulley with a rope around it connecting two masses. According to this post the work done by the rope on the two mass system is 0. The explanation of this post makes sense to me; the blocks ...
0
votes
2answers
58 views

Isn't inertia experience by person in moving bus same as torque

When a bus moves suddenly, the person standing in it tilts backwards. This concept is explained using inertia(tendency of body to resist change in its state of motion) but when the bus moves suddenly, ...
0
votes
0answers
31 views

Two spheres falling through a pipe

Imagine a pipe of radius $a$ perpendicular to the ground. A liquid flows in the pipe. Now you throw (instantaneously) two balls with radius $b$ (where $b << a$) through the pipe: one through the ...
0
votes
3answers
97 views

Work and energy - explanation of definition [duplicate]

I have a question about the definition of energy. the definition is "ability to do work". what does it mean? what is the ability that the definition talks about? what is the meaning of ability in ...
0
votes
0answers
31 views

Invariance of forces

In Newtonian mechanics, the inertial forces depend on the reference frame and the other forces are invariant. Are they still invariant when special or general relativistic effect are involved?