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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Will terminal velocity exist on this imaginary planet?

If the atmosphere of an imaginary planet is really thin like 100 particles per cubic centimeter (density of the closest resemblance of vacuum made on Earth) and has mass say, 15 times than that of ...
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2answers
36 views

Does juggling faster less work then juggling slower?

I got this idea when juggling. Let's say three balls with the standard technique. When I throw the balls higher it is harder (more work), but since it takes more time for them to fall back I work less ...
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1answer
53 views

Why does the water rise upwards when the bottle fall down with accleretion $>>g$?

When a medium-sized bottle filled with water quarterly falls from a height with acceleration $g$, the water remains calm. But when it falls with acceleration $>>g$, the water abruptly rises up ...
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131 views

Understanding of the $m v^2/2$ formula for kinetic energy

I have some problem to intuitively understand why the kinetic energy grows quadratically with the velocity (at least in non-relativistic case). Assume the following experiment: we launch an unmanned ...
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47 views

How to check if a system is in SHM in two spring systems?

I must determine if the system (a) is in SHM. I must arrive to the conclusion that there is a linear restoring force such that $a=-w^2x$. The solution's manual affirms that according to Newton's ...
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1answer
27 views

Finding the moment of inertia of a lever [duplicate]

I am required to find the moment of inertia of the lever for a project in physics. This is my attempt: Please note that we have not been taught this yet in class so i have not been taught this ...
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2answers
48 views

Can the relative position of two masses connected by a spring become negative?

Consider the following diagram. Two masses of 1 kilogram each are attached by a spring of 1 N/m. The $x$-axis is chosen such that $x_1(0)=0$ and $x_2(0)=L$ where $L$ is the length of the spring in ...
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1answer
31 views

Why is energy of emitted particles negative?

recently I had one problem here, and in comments I got interesting thing written by user Sofia. Unfortunetly, the topic is in hold now and I can't ask her more. Here is the comment: Radio-activity ...
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1answer
61 views

Pushing over a block [closed]

Consider a rectangular block of mass $m$ and uniform density resting on a frictionless surface. The height is $h$, the width $w$, the length $l$. Consider one of the faces with dimmensions $l$ by $h$. ...
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4answers
79 views

Centripetal force for non-uniform circular motion

For uniform circular motion, centripetal force is given by $$\dfrac{mv^2}{r}.$$ But what will be the centripetal force if the circular motion is non-uniform in the sense that linear velocity is ...
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1answer
24 views

Maximum velocity on Unbanked roads and why should friction be more than centripetal force? [closed]

Why is maximum velocity on unbanked circular road given by $\sqrt{urg}$ where $u$ is coefficient of friction, $r$ is radius of circular track and $g$ is acceleration due to gravity? Why should ...
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2answers
70 views

Problem in Euler-Lagrange imply Newton

I'm self-studying Mechanics and I have a little problem: We can see that in Landau's book or in Wikipedia that when we inject the lagrangian in Euler Lagrange equation the term $\frac{\partial ...
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1answer
30 views

Newton's gravity formulas for ellipses

A few times I've come across formulas, which are identical for circular and elliptical orbits, except that for the second ones you substitute $r$ with $a$, where $r$ is the radius of a circular orbit ...
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2answers
157 views

Why do you have less control over a bicycle with a broader steer?

I recently had an argument with someone on why a bicycle with a broader steer gives you more control. We both had different answers to this question and neither could convince the other. First a ...
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2answers
60 views

How does a roller coaster car stay on the track on a curve [closed]

Say a roller coaster car is going up a ramp to a drop. At some point it needs to traverse a curve to get to the drop. In general, since the car is constrained to the rail, how is it able to move ...
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1answer
51 views

Where does the block get the energy from?

Let there be a block of mass $m$ on a frictionless surface. A boy of mass $M$ exerts an invariant force $F$ on the block & does positive work on the block by displacing it by $d$. By Law of ...
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2answers
38 views

When an applied force that exactly equals the max static friction is on an object

When an applied force that exactly equals the max static friction is on an object, does the object start moving at this point?
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1answer
69 views

Difference in mass shown on balance and real mass

Milk of density 1000 ${kgm}^{-3}$ is poured at a steady rate of 0.1 ${kgs}^{-1}$ into a measuring bowl on top of some accurate scales (measuring the force converted into a mass)from a height of ...
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1answer
72 views

Force between two blocks on a friction-less surface [closed]

The question is, A single horizontal force $F$ is applied to a block of mass $M_1$ which is in contact with another block of mass $M_2$ as shown in the figure. The surfaces are ...
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1answer
49 views

Friction because of Earth's rotation

Is there some force of friction that acts on bodies due to rotation of Earth. We all know earth is an non inertial frame. If there is some frictional force is there some way to prove it. What i mean ...
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1answer
94 views

What is matter made of in the light of Quantum Mechanics? [closed]

I've always wondered what matter (particles, force particles, etc.) was actually made of considering the fact that quantum mechanics has shown us that particles can actually act as a probabilistic ...
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3answers
71 views

Reconciling Units in Classical System Analogies: Why Does Torque Have Units of Energy?

In classical physics we often cast an analogy between translational and rotational systems Force < > Torque Energy < > Rotational Energy Momentum < > Angular Momentum and considering SI ...
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1answer
20 views

belts and balls, correct size of holes

I'm working on a robot that has to transport a set of balls up at a 60 degrees angle. In order to do this I want to use a belt system with holes in it. Now my question is how big do these holes have ...
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2answers
63 views

How to take in to account torques applied at different points

Suppose we have a rigid body with known moment of inertia through some axis ($J$) and that there are multiple torques being applied in different points in that body. I know that for a rigid body, the ...
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1answer
205 views

Drag force on a flat plate

The solution for this apparently is $\frac{1}{2}C \rho A V^{2}$ where $C$ is the drag coefficient, $A$ is the area and $\rho$ and $V$ are the wind density and velocity. Let's do it without the drag ...
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1answer
190 views

Can a ball stay still while laying on a inclined plane?

Suppose there is a ball on an inclined plane. So, there are three forces acting on it: normal force from the plane, gravity (which can be decomposed in the component of gravity perpendicular to the ...
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2answers
103 views

Why isn't work relative?

Acceleration and displacement can be defined relative inertial frames. For example, a body moving with constant velocity on top of another moving with the same velocity will have zero displacement ...
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1answer
40 views

Horizontal distance covered by an object from an initial height to the ground

We are given: An angle $\theta$ with respect to the ground, its initial height $h_0$ and the final distance $d$. How can we find the initial velocity from this information? I tried a bunch of things, ...
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1answer
159 views

How to calculate the buoyant force on a balloon at different altitudes [duplicate]

For a project into balloon simulation I'd like to know how the force on a balloon changes with altitude: I know that the Buoyant force on a balloon is: $F = (\rho_{air} - \rho_{helium})gV$ Using ...
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2answers
212 views

A spring with two masses in an inelastic collision

An ideal spring is attached to a wall, and the other end is attached to a mass $m$. The spring is initially compressed a distance $x$. After it is released, the mass collides with another mass $2m$ ...
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1answer
48 views

When sliding down steep hill, is it safer to go down back or front against the hill? [closed]

Assume you are sliding down a steep hill. Is it safer to go down with your back against the hill or the front of your body against the hill? I assumed that since the surface area of your body which is ...
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2answers
75 views

Application of Newton's third law

By newton's third law , we know that every action has an equal and opposite reaction .We move left when we push slightly on the right and move forward as we push backward . But how do rockets , ...
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1answer
45 views

Restoring Force

Consider a pendulum hanging straight down. Say I pull it to the $\textbf{right}$ some angle $\phi$. Using Newton's laws in polar coordinates, I find that in the that force in the $\hat\phi$ direction ...
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1answer
29 views

Normal force on varying mass

A cart filled with a mass $m_0$ of sand leaks it at a constant rate of $\mu \ \mathrm{kg/s}$ through a hole at the bottom of the cart. Suppose that the cart is moving on rails. Find the ...
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2answers
177 views

Why is there a static frictional force on an object that rolls without slipping?

It is clear that if a frictional force must exist on an object that rolls without slipping, it must a static frictional force because the contact point of the object with the ground does not move. I ...
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4answers
105 views

Find a central force given the orbit

I've been trying to solve the following problem for a long time. Let's consider a particle of mass $m$ in $\mathbb{R}^3$ with polar coordinates $(r,\theta,\phi)$. The particle moves on the orbit ...
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1answer
129 views

Work done by Internal Forces

Why is it that internal forces do not change the potential energy of the system? Assume that a man stands on earth with a dumbell. If the dumbell is the system, when it is raised a height h, the work ...
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1answer
86 views

Finding equilibrium of mechanical system

A system is described as follows: Consider a system consisting of two rotating bars of length $l$ and with uniform mass density and each with total mass $m$. The bars are attached to a common ...
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2answers
141 views

Find the minimum force that has to be applied to the block $m_1$ so that the other block just begins to slide

This is a problem from the book 'Problems in General Physics' by I E Irodov. Two blocks of masses $m_1$ and $m_2$ are placed on a rough horizontal surface, connected by a light spring. Find the ...
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2answers
163 views

Time of flight for a projectile with stated initial velocity and size at various distances

I've been mooching round the internet looking for an answer to this one and can't find a ready resource, hence the question. In short, I'm trying to discover the flight time of a shotgun pellet at ...
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4answers
253 views

If the velocity vector of a moving particle is always perpendicular to the position vector, is the path a circle?

A Newtonian physics question: If the velocity vector of a moving particle is always perpendicular to the position vector, is the only possible path a circle? What if the magnitude of the velocity ...
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2answers
53 views

How would an earth-spanning ring around the equator behave?

If a ring/belt would be constructed of a sufficiently strong material around the entire equator at 100m height from the surface assuming the land/water beneath is flat (no mountains get in the way), ...
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2answers
119 views

Electrical force between two objects

I tried to solve the following problem: There are 2 objects . The object m1 with charge q and the object m2 with charge q.(same charge).The object m2 is connected with a rope to the ceiling. at the ...
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1answer
88 views

How to discover the $F = m\cdot a$ equation from scratch? [duplicate]

Is there a paper or a book that conceptually 'discover' the Newton's famous formula? I've been thinking about this equation, and I really don't know it for sure. Did Newton empirically noticed that ...
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3answers
102 views

Why doesn't an orbiting body keep accelerating?

As a physics newbie I'm trying to get a grip on basic orbital mechanics. I think I'm beginning to get grasp on how bodies interact with each other. When a body approaches another body it accelerates ...
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2answers
159 views

Calculating velocity change after impact?

Let's say there is no gravity here and objects won't crush. We have 2 rocks with $m=10\text{ kg}$. First rock has velocity $v_1=0\text{ m/s}$ and second $v_2=10\text{ m/s}$ (flying in leftward ...
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2answers
436 views

Why is the force of Friction less than the force applied on the block in this situation?

This is a seemingly basic mechanics problem but I'm having a dilemma in understanding what happens. You start with two blocks, one on top of the other (the bottom block has a larger mass than the top ...
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1answer
75 views

Kinematics and Energy - Finding the work done in projectile motion

If you are asked to find the work done by gravity on a projectile, the force will obviously be the mass multiplied by gravitational acceleration. What will the displacement be, the horizontal or ...
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1answer
99 views

Follow up question regarding: Deceleration rate of objects of different mass but the same otherwise

My first question was answered here: Deceleration rate of objects of different mass but the same otherwise . But based on that, here is a follow-up question (I also edited my first post with the ...
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4answers
123 views

Equations of graphs

I am doing a practical write up of an experiment I did. Here is a graph using the raw data I got. What is the general formula of this graph, and what do I need to do in order to make that into a ...