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.

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Sliding ladder kinetic energy in generalised coordinates [on hold]

This is a problem from Hand and Finchs' Analytical Mechanics, in a chapter looking at holonomic constraints and generalised coordinates in Lagrangian Mechanics. A ladder of length $L$ and mass $M$ ...
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30 views

Conservation Laws and Isotropic Time

In most dynamics books I've read they refer to conservation laws and their associated symmetries. I know that the conservation of momentum is a result of the homogenity of space angular momentum is ...
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2answers
29 views

why does a rotating ball attached to a string increases its tangential speed?

If a ball is attached to a rope and I push it in it will increase if tangential speed (by conservation of angular momentum). Should not a tangential force than makes work be responsible for this?
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1answer
19 views

What can I say about a graph depicting orbit a particle has gone through? Acceleration VS friction

I have an orbit in which a particle is told to have gone through. There is a straight part, and a curved part. I am asked to mark the right statements, which are: a. Without any further data, there ...
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45 views

Mechanical energy? [on hold]

A particle of mass $2\,\mathrm{kg}$ is attached to one end of a model spring that is hanging vertically from a fixed point O. The spring has stiffness $4$ and natural length $1\,\mathrm{m}$. ...
2
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1answer
83 views

Moving Around Space Without Propellant [on hold]

A mechanism as shown in following picture is floating freely in space. Concentrating on the main components first, which is the long rod in the middle with another 8 smaller rods connected to it, ...
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1answer
19 views

What is meant by “method of approximate numerical method” or “method of digital computer” for solving the differential equation of resistive force?

I was reading "motion against resistive forces" in Newtonian Mechanics by A.P. French; here is the excerpt: [...] In general, the resistive force $\mathbf{R}$ is is a function of speed, so that ...
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0answers
60 views

Centrifugal And Centripetal Forces [on hold]

Imagine a long rod floating in space(negligible gravity). On this long rod are attached 8 other smaller rods with a massive sphere attached to them at the end. They are connected with the long rod ...
0
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1answer
40 views

Maximum range of projectile from elevation, simply?

Let us say you have project a ball at velocity $u$ from a cliff hight $h$, and we want to find the maximum range of the ball. Ok so you could do this using equations of motion (for constant ...
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0answers
11 views

How to calculate the steps needed for a motor to rotate a circular object in a pulley configuration? [on hold]

I have a stepper motor with 200 steps per revolution and a pulleys configuration as following: 3 pulleys with 100 mm diameter each on 1184 mm PCD and are equally spaced (120 degrees) from each other. ...
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1answer
30 views

How is the kinetic energy of the wind transferred onto a lift based wind turbine?

The rotor blades of a lift based wind turbine are shaped like airfoils, so the wind flowing around them creates a lift force which in turn moves them around. From a thermodynamic viewpoint and like ...
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0answers
30 views

Hooke's law question of physics [on hold]

A spring has a length of 9cm when loaded with a 200g mass. The 200g mass is replaced with a 100g mass. What is the new length of the spring?
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3answers
533 views

Can Lagrangian mechanics be justified without referring to Newtonian mechanics?

Are there any ways of justifying Lagrangian mechanics as a foundation of classical physics, without referring to Newtonian mechanics? In other words, what is the deeper reason or intuition why ...
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29 views

How does the elasticity of a ball influence its behaviour during collision?

The problem I am trying to solve is as follows: A football made of rubber with mass $m$ rolls on a table at speed $v$ and angular speed $\omega$ until it hits a player. Some sort of deformation ...
0
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1answer
59 views

Which point in the graph does a parachute open?

The diagram represents speed-time for a sky diver. He falls freely from an aircraft then opens a parachute and later lands safely on the ground. At which point did the parachute fully open? ...
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0answers
13 views

What motor is required to run lift 200 kg on 25 feet? [closed]

I am working on a Lift project for a wheel-chair , & i am wondering what power of motor and pulley is required for 200 kg , 1 person lift.
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0answers
18 views

Find how much does the spring extend [closed]

A mass m body is attached to the spring and rests on the board so the spring is not stretched. The board starts to move with an acceleration a. How much does the spring stretch at the moment when the ...
0
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1answer
46 views

Time to fall in a non-uniform gravitational field

In an uniform gravitational field the loss in potential energy (the work) done by gravity is given by $\text{-}mg\Delta h$ and the time to do so (assuming no friction and no initial velocity) is given ...
2
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2answers
76 views

A car with constant speed doing a turn

Let's say we have a car with four wheels and the center of the car has a speed of 50km/h. There is no friction or air resistance. If the car is moving straight each wheel will also have a speed of ...
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42 views

physics question.. please help! [closed]

A 68-kg woman stands on frictionless level ice with a 0.8-kg stone at her feet. She kicks the stone with her foot so that she acquires a velocity of 2.7 cm/s in the forward direction. The speed ...
0
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1answer
25 views

Pendulum clock delay of time everyday caused by Earth's rotation [closed]

I need to solve this problem: A pendulum clock which gives the correct time at a certain place on the Earth's ground is taken 320 meters high (from the ground) to a tower's very top. Q: How much ...
0
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1answer
67 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 ...
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32 views

What is the velocity of a ball on a quarter-circle ramp (with friction)? [closed]

A block of mass m is positioned at the top of a quarter-circle ramp with radius R and friction coefficient μ I would like to find the velocity of the block as a function of μ, R and θ So far I ...
3
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2answers
56 views

Force amplification and Newton's third law

Pascal's principle in hydraulics leads to force amplification which is a common feature in hydraulic brakes and hydraulic press. A small force applied on a piston of small cross sectional area ...
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0answers
25 views

moment of inertia of an object [closed]

A thin wire bent into the form a three sided, block-shaped "|__|" with each segment of equal length b. Find the moments of inertia of each about their symmetry axes. My work: So the ...
14
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3answers
1k views

Does holding weights allow you to run faster?

I'm not talking about training with weights so that when you run without them your muscles are used to pushing more weight so with less weight it'll be easier, I'm talking about while actually holding ...
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3answers
74 views

Ball on a slope with hollow

The experiment shown in the image suggests that ball B will reach the goal faster than ball A although the balls have identical properties and they start from the same height. The authors even ...
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0answers
26 views

Finding minimum force to pull box A [closed]

box B is attached to the wall by a rope, while box A is pulled by force F, where mA= 5kg / mB = 2kg. btween B and A Ms= 0.3 Mk=0.2 and btween A and ground Ms=0.3 Mk=0.2 what is the minimum force (F) ...
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0answers
28 views

Distance between two parts of a train [closed]

A Train of mass $M$ is traveling with a uniform velocity on a level line. The last Carriage whose mass is $m$ becomes uncoupled at an instant. The driver discovers it after travelling a distance ...
2
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2answers
74 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 ...
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1answer
29 views

Definition of mechanical impedance

Mechanical impedance is in the simplest (yet common) case defined as: $$ Z_m = \frac{F}{v} $$ where $F$ is force (let's assume 1D case) and $v$ velocity of the object (let's assume point of mass). ...
2
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0answers
86 views

Minimum energy required to roll a cuboid through $90^\circ$ [closed]

I'm stuck on this textbook question about the minimum energy required to roll a cuboid through $90^\circ$ from an upright position to a horizontal position (see image). I believe the correct answer is ...
2
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1answer
36 views

Calculating pendulum rate variation due to change in force of gravity over arc of swing

Hi all and thank you in advance for any insight into this problem. I'm a journalist working on a story on precision pendulum clocks and specifically on the isochronism of pendulums. I note that the ...
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3answers
72 views

Acceleration of a particle moving along a straight line

If a particle moves along a straight line, then can we say that the acceleration should be zero? and if not, then why? If the equation of the motion is linear, then the velocity is constant and if ...
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43 views

Why is velocity different than the higher derivatives of position?

Why is a body only maintaining its state of uniform motion or rest, but not its acceleration or any other higher derivatives of position?
2
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2answers
115 views

Angular momentum with respect to the centre of mass

I have been told [Warning: I leave this because it's what I asked and allows to understand the dialogues in the comments, but Azad, whom I thank, has pointed that the formula does not hold in general ...
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1answer
37 views

Modeling the system as an equation

Consider a system in which you have a rope connected to 1 pull above (A) which connects to a pull below (B) in which some object of mass 10kg is attached To the pully(not the rope). The rest of the ...
2
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0answers
32 views

How to find the maximum torque to apply to a robot joint to have realistic movement? [closed]

I am a computer science student. I am trying to simulate a locomotion of a legged robot. The weight and dimensions of the robot: A rectangular torso has 1 Kg, (0.15m*0.3m*0.03m) (width * length * ...
3
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3answers
96 views

Force and Acceleration, is there a delay?

Suppose we have a mass $m$. We can talk about two of its parameters : The net force applied on it $f(t)$ and its net acceleration $a(t)$. I want to know whether there is any delay between $f(t)$ and ...
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1answer
32 views

What stops the middle point of a power line from falling?

Say you have a system that is a uniformly weighted string with slack suspended from two points; i.e. a power line. There are three forces acting on any given point on this string: string tension ...
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1answer
34 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
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0answers
21 views

Rotational motion of a cylinder [closed]

I was solving a problem related to rotation, and cannot get to the exact answer. The question is as follows: A cylinder of mass $m$ rests on a carriage as shown. Calculate the maximum acceleration ...
1
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1answer
41 views

After a glancing collision, why do air hockey pucks spins around in circle?

For a lab testing the conservation of momentum, I had to hit an air hockey puck so that it would hit another stationary puck in a glancing collision. After the pucks collided, they travel their ...
1
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1answer
36 views

Where would be the source of thrust for a rocket thruster in space?

I am making a game that involves spaceships and I was building an engine block. That engine block spawns a "thruster fire" under it that represents the...thruster fire. My question revolves around ...
4
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4answers
337 views

Dodging paintballs

I was recently watching The Matrix, and was considering the speed at which one needs to move to literally dodge a projectile. Now, in real life, it is impossible to dodge bullets as such a feat would ...
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1answer
33 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 ...
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3answers
84 views

Confused by answer to mechanics question [closed]

I am confused by the answer to this question. Well, I am trying to explain my thought process about this. I used net energy in the system to calculate the maximum speed. So I assume at max velocity, ...
2
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2answers
34 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 ...
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1answer
25 views

What happens with an originial force if a part of it creates a torque?

Let's say I push with an angle of 45 degrees at an object with a force of 100 N. Since the angle is 45, we would have a torque $\tau = 100 * sin(135) * r = 71N*r$ Since the force was not ...
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2answers
48 views

What forces are applied as a car exits a curve with constant speed?

Imagine a car taking a curve with constant speed. Assuming no friction or air resistance all we would have would be centripetal force. As the car's front wheels straighten to exit the curve the ...