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.

Filter by
Sorted by
Tagged with
0
votes
1answer
31 views

Acceleration of a sphere with cavity in the incline

Does the object in the figure above undergo an uniformly accelerated motion? (Let's assume that the object rolls without slipping, ignore $\theta$) I tried to find acceleration using free body ...
0
votes
2answers
62 views

Equations of motion: Calculate location of point [closed]

The scenario is that a user is dragging an object on a touchscreen. I want to calculate the position of the object as the finger drags it across the screen. I also want to account for any acceleration ...
0
votes
0answers
36 views

How to calculate the launching velocity when there is gravity to be considered?

I think i got very close to the Solution. First, i had to find the velocity at which the ball is launched. I used energy Conservation formulas and find that. But the expression of the velocity was ...
1
vote
1answer
66 views

How to understand Newton's law of universal gravitation?

Hi I am a high school physics student and I am currently struggling to grasp the concept of Newton's law of universal gravitation. I am really confused with how this works. So do all objects attract ...
0
votes
0answers
17 views

Moment of impulse simple problem. (have answer, need to find a way to do it) [closed]

Problem is: "Flywheel is rotating with frequency of 20 Hz, where it's angular momentum is equal to 2000 kgm2/s. When angular momentum stops, flywheel stops after 1000 revolutions. Find moment of force ...
3
votes
1answer
16 views

Way to reduce lateral movement of a rod when trying to calculate the mass moment of inertia using bifilar pendulum?

Basically I'm trying to measure the moment of inertia of a hollow rod using bifilar pendulum. I will rotate the rod, and measure the period, and use the written formula to calculate the moment of ...
0
votes
1answer
51 views

Determining acceleration in order to meet a space-time-velocity reservation

An Example A train on a single line track is told to be at position $x_{res}$, at time $t_{res}$, and to be moving at exactly $v_{res}$ when it hits that point. Where $_{res}$ denotes the reservation....
0
votes
0answers
29 views

Proving the law of the lever

The image describes what would happen if there is no equilibrium. For the bar to balance, I will need to have $B$ accelerate upwards by the same amount $A$ does before the movement starts. I have $a_A=...
2
votes
1answer
40 views

Angular velocity, angular acceleration and it's observer

I was solving the problem above and realized that I was wrong somewhere. I did two approaches but one didn't work well. 1. let one end which is at hold be the point we calculate torque. Then, $\...
-1
votes
0answers
21 views

Acceleration and tension [closed]

If block A (weight 200kg) is being pulled at a 20 degree angle by block B (weight 2000kg), blck B has a pulling force of 3000N & (friction of block B=1500 / block A=1000) what is the acceleration ...
0
votes
0answers
38 views

Prove: angular velocity does not dependent on the vector stay fixed with the rigid body

From definition of the angular velocity of a rigid body: $$\frac{d\vec c}{dt}=\vec \omega \times\vec c$$ with $\vec c$ is a vector fixed in the rigid body. Now, choose a different vector $\vec a$ ...
0
votes
1answer
41 views

Why does a falling ladder $y$ component force greater than the $x$ component force?

I have a ladder at 30* against the smooth wall and it accelerates down and to the left when it falls to a rough ground. It also pivots at the bottom. I understand that the the force of gravity is ...
0
votes
1answer
14 views

Finding the minimal radius of body in elliptic motion

Assume I have a body with mass $m$ with particular velocity $v_0$, that is is being pulled by a radial force which is linearly proportional to the radius $r$, which is the body's distance from the ...
0
votes
1answer
31 views

Work of a conservative force

Given a conservative force $\mathbf{F}=-\nabla V$, how do I show that $$ W=V(\mathbf{x}_2)-V(\mathbf{x}_1)\quad ? $$ I can start as follows $$ W=\int_{\mathbf{x}_1}^{\mathbf{x}_2} \mathbf{F}\cdot d\...
-1
votes
0answers
22 views

The potential energy curve of a two particle system V(R) is shown below. which part of the curve corresponds to repulsive potential? [closed]

The potential energy curve of a two particle system V(R) is shown below. which part of the curve corresponds to repulsive potential?
0
votes
2answers
70 views

Confusion about energy conservation

Suppose a rocket at rest turns on its jet and is now moving with kinetic energy $\frac12 mv^2$ in the lab frame. Suppose the efficiency was maximum so that exactly $\frac12mv^2$ of chemical energy was ...
0
votes
0answers
68 views

Ridiculously difficult Newtonian physics problem [closed]

I have been trying out with this one for a long time with no luck getting the exact expression. I am pretty sure this is somehow related to Kepler's third law but unable to establish the connection ...
0
votes
2answers
52 views

Is it true that a machine that generates thrust without blowing anything out not invented yet?

If yes. Am I correct to to say such machine does not conflict with the law in Physics and thus, it can be possibly invented? I mean a machine that does not rely on external forces such as a machine ...
0
votes
1answer
25 views

Direction of the frictional force

Why is it said that friction always acts in the direction opposite to the relative motion at the point of contact with the surface? When a sphere is rolling down an incline for example, the friction ...
0
votes
0answers
10 views

What is a real world example of white noise excitation in the dynamics of macro objects (other than as a model for sensor noise)?

The literature on stochastic processes (Ornstein-Uhlenbeck, Langevin) is not very clear as to the motivation behind using the Brownian motion in the dynamics. Are there any real world applications of ...
0
votes
0answers
51 views

A strange gravity question [closed]

A superconducting gravity meter can measure changes in gravity of the order ∆g/g = 1 × 10−11. You are hiding behind a tree holding the meter, and your 63 kg friend approaches the tree from the ...
-3
votes
1answer
21 views

I need help topic: acceleration [closed]

in science class we are doing a lab it deals with acceleration. how far a golf ball goes per like 2,4,6, seconds. and one of the questions of the lab is : "IF YOU WERE TO REPEAT THIS EXPERIEMNT ONE ...
0
votes
0answers
17 views

How do I correctly model this system of torsion springs?

I am currently designing a symmetric parallel mechanism that can be modeled as follows: Here, $\tau^j$ denotes actuator moments and $k_i$ are torsion springs constants. For a specific point in the ...
0
votes
1answer
61 views

Green's Functions

I am having trouble understanding how to apply Green's function to an impulsive forcing function. I am having trouble understanding how to use Green's function to solve for the motion of a driven ...
0
votes
0answers
20 views

Several questions about Newtonian World Index Algebra [closed]

Which of the following quantities are meaningful and which are not? a) $A_{ij}=B_{ik}A_{kj}$ (Meaningful, because $k$ indexes cancel each other. How can I describe this rule, I don't know.) b) $A_{...
0
votes
1answer
58 views

Basic Understanding Of Angular Momentum

I am trying to understand angular momentum in the same visceral way that I understand linear momentum, e.g., if someone rolls a bowling ball towards me then it is “natural” to me that I must apply a ...
-1
votes
0answers
20 views

Newton's law of motion [closed]

A 2 m long ,500g rope pulls a 10 kg block of ice accross a horizontal,frictionless surface. The block accelerated at 2m/s^2 . Is the mass of the rope considered to find the force?
0
votes
1answer
37 views

The role of friction in rolling without slipping

I am confused about this whole subject. Let's suppose we have a disk standing still upon the ground. Now let's say someone inside the disk shoots a projectile to the left. From momentum conservation ...
0
votes
1answer
28 views

Feynman's Reversible Machine Argument

In Feynman's Lectures on Physics, in the lecture on the conservation of energy, he makes the following argument: Consider weight-lifting machines—machines which have the property that they lift ...
0
votes
2answers
36 views

Why do springs have a linear relationship?

Why does: F = k*(change in position) Why can't the relationship be quadratic or higher ordered?
0
votes
0answers
37 views

Rotating triange colliding with wall

Imagine a freely moving equilateral triangle in the x-y plane with a given velocity $\vec v$ rotating around the z axis at its center of mass with an angular velocity $\vec \omega$. Now this triangle ...
1
vote
1answer
59 views

Basic two-body dynamics [closed]

I'm trying to solve this easy example problem from my Physics textbook dynamics chapter. The question is "How must the weights w1 and w2 be related in order for the system to move with constant speed?"...
1
vote
2answers
80 views

Why is the center of mass the pivot of rotation?

Suppose a ball moves horizontally to the right and hits a vertical stick at a position closer to its upper end. I understand intuitively, the stick will have linear and angular momentum, and that it ...
0
votes
3answers
43 views

How do we get definitions of fundamental terms from a formula like the Work-Energy Theorem?

I’m a senior taking AP Physics C, and I’m currently losing my mind over this question. I get that work is essentially a measure of whether a force is “successful” or not in displacing an object in ...
0
votes
0answers
16 views

Thrown distance from initial force [closed]

So, a hypothetical situation has been posed by a friend playing a game of D&D. He's curious how far a frost giant could throw a person. The game gives rules for calculating the creature's maximum ...
0
votes
0answers
23 views

Tilted pole harmonic motion

This is a question i thought on myself while swinging from a hammock. A pole with mass $m$ and length $k$ is suspended in air by two mass-less strings one at each end of the pole. One string has ...
0
votes
3answers
75 views

Analysis of stacked blocks motion [closed]

$F_b$ force is being applied on the top block. The surface is frictionless but there exists friction between both the blocks. Let the frictional force acting on the top block be $F_f$. Can $...
0
votes
0answers
14 views

How Traction differs from Road friction?

I am an aspiring mechanical engineer & me n my team are going to manufacture a buggy for which i am going to design & manufacture the braking system. I have a problem in understanding The ...
0
votes
0answers
31 views

Why is $F = -dP \cdot dA$ in a fluid?

I was reading the Wikipedia article on Pressure-Gradient force (image above) and one line didn't make sense to me: $$F = -dP \cdot dA$$ Force is pressure times area, but where did the negative sign ...
2
votes
1answer
64 views

Is there an equation that relates angular acceleration to centripetal acceleration? Tangential to centripetal?

Is there an equation that relates tangential and centripetal acceleration? I ask this question because it's been on my mind ever since I solved a problem involving the giant swing ride commonly seen ...
0
votes
0answers
31 views

Newton's Cradle counter-example [duplicate]

When releasing two balls from a Newton's cradle, both with mass $1 kg$ and velocity $2 m/s$, they have momentum $4 kg m/s$ and kinetic energy $4 kg m^2/s^2$. Assuming elastic collisions, these will be ...
0
votes
1answer
37 views

Moment of force about a point definition

In defining the moment of a force about a point as "the tendency of one or more applied forces to rotate an object about an axis [going through a point, hence also about a point]", I see it logical to ...
0
votes
1answer
81 views

Is there any physics book like Newtons principia mathematica?

Firstly that it is practically undecidable whether it's a math or a physics book due to its elegant formal mathematical style despite being about the natural world. Secondly no coordinates, not even ...
0
votes
1answer
36 views

Is there a difference in energy walking with and against Earth's rotation?

If the amount of energy required to accelerate an object is dependent on an object's speed, and the earth is spinning, shouldn't take more energy to walk with the earth's rotation rather than against ...
-1
votes
0answers
40 views

Could we make a orbital kinetic strike weapon big enough to destroy a city? [closed]

i was playing call of duty ghost recently and i realized they were using a kinetic orbital strike weapon and i was just wondering if it would be possible and effective at the same time I've watched a ...
0
votes
1answer
35 views

Does “inflation” eliminate the requirement that the big bang distributed an infinitely dense kernel of mass?

My admittedly limited understanding of the big bang is that it was an event that expanded spacetime itself along with the kernel of infinitely dense material that coexisted at the moment of the big ...
0
votes
3answers
72 views

On force being directly proportional to the rate of change of momentum [duplicate]

Newton's second law says that $F_{Net}=\frac{dp}{dt}$. I do realise that when the net force on a body is zero it keeps its current velocity, so one can infer that the force is somehow related to ...
1
vote
2answers
61 views

Gravitational Oscillation and Kepler's Third Law [duplicate]

I want to figure out the motion of a comet that can somehow pass freely through the sun (mass much, much greater than the comet's so that its movement is negligible) if it starts out stationary ...
-1
votes
0answers
38 views

Classical physics [closed]

A stone of mass 0.25 kg tied to string executes uniform circular motion with a speed of 2 m/s of radius 2m .The magnitude of the tensional force acting on the stone is __________.
-1
votes
1answer
28 views

Moving objects released

There is a balloon moving upwards with a small object attached to its bottom. If the object is released after some time, then will it start moving downwards suddenly, or will it move up a little with ...

1 2 3 4 5 251