Recent content by user5

  1. U

    Conservation of energy- basics

    The mass is released at height h above the spring, how far will the spring move? Ei=mgh,Ef=kx2/2+mgx...why the second equation isn't Ef=kx2/2−mgx? Since it is below the "zero".
  2. U

    How the tension is calculated?

    mv^2/L is the radial force that need to be equated with the tension force...but the torque mgsin 90 = mg
  3. U

    How the tension is calculated?

    A massless rod of length L attached to mass m and with axle to cart of mass M. The cart has a shape of equilateral triangle (edge L). the cart is at rest and its center of mass is above x=0 and a rod is perpendicular to the ground. the cart is free to move without friction. at time t=0 the mass...
  4. U

    Find the place of the explosion

    thank you very much! may you help me with solving this equation?
  5. U

    Find the place of the explosion

    A missile is fired at speed V0 at an angle 450. The missile exploded into two parts when reaches the maximum height. The part of mass m1 is thrown back at speed V1 relative to the missile speed before the explosion (V1>V0). From the shot till the explosion the wind was blown that exerts a...
  6. U

    Calculate Angular Velocity with 3 Masses and Constant ω

    But the answer states before it is mL2ω why?
  7. U

    Calculate Angular Velocity with 3 Masses and Constant ω

    My goal is to equate the angular momentum before and after...so I'm asking how to make the equation before the separation...
  8. U

    Calculate Angular Velocity with 3 Masses and Constant ω

    yes indeed "perpendicular to the triangle "! At the beginning the axis of rotation passes through the center of mass, (of the triangle, rcm=(0,L√3/3))
  9. U

    Calculate Angular Velocity with 3 Masses and Constant ω

    Three equal mass, m are conected to vertices of an equilateral triangle, with edges of length L. Edges are massless.The triangle rotates with constant angular velocity ω about an axis through its center of mass, perpendicular to the triangle plane. At t=0 mass 1 is released, at a very short...
  10. U

    Calculating Impulse of Normal Force in a Frictional System with Thrown Ball

    For formulating the change in momentum of the ball (to be equating with the impulse of the net force): at first it is given an initial momentum p i=v0sinθ after Δt wouldn't pf still have the same value as at the initial momentum?
  11. U

    Calculating Impulse of Normal Force in a Frictional System with Thrown Ball

    1.Is the analysis at the time when the ball is landing on the stick (because then pfinal=0 pi=-v0sinθ )? 2.Why there is no momentum from the normal force between the ball and the stick? 3. Is the normal force between the stick and plane not constant because of the normal that acts between...
  12. U

    Calculating Impulse of Normal Force in a Frictional System with Thrown Ball

    Yes there are. Still I can't see how to calculate the impulse of the normal force between the stick and the surface... I thought that the change in momentum is 0-(-mv0sinθ), and when I show the forces that act on the stick N will change because the N that come from the ball will stop acting...
  13. U

    Calculating Impulse of Normal Force in a Frictional System with Thrown Ball

    Homework Statement Stick of mass M resting on frictional surface with friction coefficients μk=μs. From the center of the stick at time t=0 a ball of mass m thrown to the right with an angle θ above the horizontal and with speed v0. As a result of the throwing there is an impulse on the y...
  14. U

    Rotating cylinder on inclined surface

    Why mgsinθ would not provide the needed ability to slip?
  15. U

    Rotating cylinder on inclined surface

    Why does at Δt2 friction do no work? How do I know that all the way down there is only a static friction?
Back
Top