Tagged Questions

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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Infinite pulley system

http://www.physics.harvard.edu/uploads/files/undergrad/probweek/sol43.pdf Hi, I've been trying to solve this question for a while, I understand the first solution and also the solution to the second ...
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Second moment of area in parallel axis theorem

In parallel axis theorem why Ig second moment of area on axis passing through centre of gravity, is not zero. Even distance between axis and centre of gravity is zero.
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Difference between first newton's law and second newton's law ? [duplicate]

the first and second laws of newton are both similar, so why do we need the first law if it is the same as the second? what is the big difference between these?
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How would you explain the weight of an object in a lift accelerating up with acceleration a?

Observer in the lift:- He is unaware of his acceleration. He applies Newton's second law and got N = Mg. After that he used spring balance and found that the wait of the object is M(g+a). So to ...
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Conservation of mechanical energy isn't giving me the right answer? [closed]

I have been trying to solve this question: You are working for a shipping company. Your job is to stand at the bottom of an 8.0 m long ramp that is inclined at 37 degrees above the horizontal. You ...
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Why is the axis of rotation about O? (picture)

I'm not understanding part b. Why is the rotation about O? Shouldn't it be about C? If you do it about C you get a different answer because you'd get the same angular velocity but a different radius ...
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Conservation of energy and angular momentum

I'm writing a java program to simulate the solar system. All planets are modelled as point masses. How do I check if my solar system is conserving energy? I'm not sure how to calculate the energy of ...
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What are the orbits of satellites; circular or elliptical? [duplicate]

What are the orbits of satellites; circular or elliptical?
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Where to hit the pool ball such that it satisfies the given condition? [closed]

The question Where to hit the ball in such a way that after covering a certain distance it rolls back? You are given a pool ball and you have to find where to hit it such that it rolls back after ...
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Few questions related to Tension

I am struggling with the concept of tension in a rope. Below specific questions. I am understanding tension to be an elastic force between rope molecules. If so, is it fair to say the net tension ...
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Acceleration due to gravitational force [duplicate]

I need some help with below. So according to Newton's 2nd law, $a=F/m$, for a given mass, the acceleration depends on mass. But acceleration due to gravity is independent of mass. There seems some ...
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To what height does the ball rebound and what is the velocity of the struck block after impact? [closed]

Here is the problem. I have tried it four different times, and I will show my most recent work. [![enter image description here][3]][3]
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Pulley Friction

Why is the frictional force of a rotating pulley 0? For example, consider two masses and a string that links those masses passing through a pulley. Why do we not account for the frictional force of ...
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Am I exerting force when i am holding something? [duplicate]

So theoretically I found out that I am NOT exerting any force while I am holding something! Like Sir Isaac Newton said F=ma So technically it is true that when I hold something I am resisting it's ...
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Does force get divided among things?

If I exert a force to more than one thing at a time, will the force be divided among them or all of them will feel the same force? I mean imagine that I have tied up 3 bags of same mass with A rope ...
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Why does a top spin so well?

I know that the force of friction does not depend on surface area, but then why does a top spin better on a point rather than a region of larger surface area. For example, if I spin a top on it's ...
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Rigid Balls aligned along a line in vacuum

Recently I've been trying to visualize a situation where i have these really rigid identical balls aligned along a line so close to each other in vacuum.Now if I were to apply an impulsive force to ...
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Why $k/m$ in simple Harmonic motion equal $\omega^2$? [closed]

I've come across this thing in simple harmonic motion but never did I manage to find a reason why $k/m$ should equal $\omega^2$ and the theory behind it. People say it is done for convenience equating ...
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A drop falling in the condensed air

A drop is falling in humid air with air resistance equal $F_r = - \alpha v^2$. In $t = 0$ the drop is ideally spherical, $h$ above the ground, has mass $m_0$ and velocity $v_0 = 0$. What mass and ...
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Tension at different points of a string during vertical circular motion

For a vertical circular motion, its standard to solve for tension at the 4 common points on the circle (North, South, East, West) My question is: Is it possible to solve for tension at other ...
I have two Earths of $x$ distance away from each other. I place a spacecraft perpendicular to the centre of mass and the distance between the two Earths. If the Earths are fixed, then the spacecraft ...