1. T

    Help with moment of inertia questions please

    I would like some help with these two questions about moment of inertia please. -First question: -Second question: For the first question, I have no idea what should I do to start the...
  2. N

    forces and moment

    Hello guys i am trying to solve question A.I just need some help with the few Forces F2 and f3 when only F is applied,i think following forces would act at A Bending at A= F*b torsion=F*a Could you guy help me When: scenario 1: only f2 is acting scenario 2: only f3 is acting
  3. A

    moment of inertia problem

    For the system shown in the figure below, m1 = 7.0 kg, m2 = 2.0 kg, θ = 31°, and the radius and mass of the pulley are 0.10 m and 0.10 kg, respectively. (a) What is the acceleration of the masses? (Neglect friction and the string's mass.) Known Formulas: Torque=...
  4. T

    Inertial "moment" of a solid given an inertia tensor

    Hi all, I am programming some software computing inertial forces of some moving structure. So far, the structure have been represented as a cloud of mass points. For each mass point, inertial forces are computed using some formulas like in this article...
  5. J

    Calculate earths mass and moment of inertia

    Hi again everyone, I have a problem (in two parts) where I believe I am tackling the solution with the correct methodology but somewhere along the line I must be going wrong because cannot match my answers to the ones in the book, in fact I am way out (by a factor of 10 to the power 11 or 12...
  6. J

    Moment of inertia generic calculation

    Hi everybody, I am afraid I have come across another Moment of Inertia problem where I cannot see how to proceed to find the solution. It basically gives a cylinder, with generic length, radius and mass of values L, R and M and the fact that density of the cylinder varies linearly with the...
  7. J

    Moment of inertia of a compound body problem

    Hi everyone, I wonder if anyone can help me with a problem which has had me stuck for some time. The problem is as follows - PROBLEM A thin, flat, uniform disk has mass 'M' and radius 'R'. A circular hole of radius 'R/4' centred at the point 'R/2' from the disk's centre is then punched...
  8. K

    D'Alembert and moment inertia of wheel

    Yet another D'Alembert problem. This time a wheel (pulley?) with only one mass but this time I have to account for the moment of inertia. When I tried to frame it mathematically I wrote it down as (F_{applied}-F_{inertial}) \delta s = 0 I ended up with the following. F_{applied} = mg...
  9. O

    Moment Questions

    This question is according to the moment. A. Think about the door. When I add a force of 10N which has perpendicular distance of 5m from the hinge, it has 10*5=50Nm moment. The force is acting by the place where I added 10N. B. When I add a force of 10N which has perpendicular distance of...
  10. J

    Moment of inertia of a human body

    Hi everyone, I have come across a problem and I just don't know how to start to tackle it. The problem is as follows :- Estimate your own moment of inertia about a vertical axis through the centre of the top of your head when you are standing up straight with your arms outstretched. Make...
  11. J

    Moment of inertia for a slender rod of varying mass

    Hi, I have come across a problem where I eventually got the answers to two parts of the problem, but only after I had attempted each part first and got it wrong then, for each part sort of 'reverse-engineered' the solution from knowing what the correct solution was and although I came away with...
  12. J

    Moment of inertia of a compound body

    Good morning all, I am having trouble with a problem to calculate the Moment of Inertia of a body made up of two distinct but linked extended bodies. I have used the generic equations for these two bodies and then added the values to obtain what I thought was the solution but my answer does not...
  13. J

    Moment of Inertia Problem

    Hi, I have come across a problem dealing with calculation of the Moment of Inertia of an extended body and I just don't understand why the answer is what it is. I understand the basic concept of Moment of Inertia in general, and am aware of how you calculate this concept for a variety of...
  14. L

    Moment diagram

    for the moment diagram, why the 400Nm straight line is drawn from the point of moment to A only? why shouldnt the 400Nm straight line is drawn from the point of moment to B only?
  15. M

    Magnetic moment of bar magnet, estimate

    The treatment for the magnetic moment of a bar magnet has been exhibited in most general physics and EM texts. How can the magnetic moment of a bar magnet be reasonably estimated from the total magnetic flux passing through the magnetized material in the plane that is perpendicular to the...
  16. J

    Inertial moment variation

    Hi, I would like to ask a question, if I may: if I have a body with a calculated Inertial moment and angualr momentum at time t0, that in a space of time delta t changes, there's a variation in its kinetic energy, right? How can I calculate the released temperature in that elapsed time? Is...
  17. L

    restoring moment

    why the restoring moment in diagram 3-48 must be in anti-clockwise direction ? cant be in clockwise direction ? pls refer to the last photo ( i sketched it) , if the B' is located on the left of the G , the restoring moment is clockwise, right ?
  18. P

    Finding dipole moment vector / Electric Field problem

    Numbers 3 and 4 from the included image are giving me some issues. Help?
  19. L

    constraint of moment about an axis

    why there is no constraint of plate about a axis ? for moment about z -axis , i can have -2Bx +3By = 0 , where By and Bx = 0 which is shown in the top part of solution....
  20. J

    Help Deriving Moment of Inertia of Solid Sphere (Where did i go wrong?)

    I am attempting to derive the moment of inertia for a solid sphere by summing an infinate amount of thin spherical shells instead of disks. Sphere has radius R Shells have radius r and thickness dr I=sum(mr^2) = integral(r^2dm). to sub out dm in terms of dr, p=m/v so pdv=dm. dv of a shell...