physics

posted by .

A meter stick is held vertically with one end on the floor and is then allowed to fall. Find the speed of the other end when it hits the floor, assuming that the end on the floor does not slip. (Hint: Consider the stick to be a thin rod and use the conservation of energy principle.)


mgh=.5mv^2
1/gh=2/v^2
v=sqrt(2gh)

where g is gravity (9.8)
h is hieght of meter stick (1 meter)
m is mass

why is this wrong??

  • physics -

    mgh=1/2 mv^2

    h (cg height)=1/2
    g=v^2

    the energy is due to the mass falling, assume the mass is at the center of gravity (h=1/2)

  • physics -

    You forgot that the stick is rotating. Add in (1/2) I w^2

  • physics -

    if the center of mass is moving at speed v at the bottom when the stick is horizontal then the tip is moving at 2v
    the tip velocity = 2v = rw = 1w
    so w = 2v

    total Ke = (1/2) m v^2 + (1/2)I w^2 = m g h
    but w^2 = 4 v^2

    remember you want the speed of the tip, not the center so the answer is 2v

  • physics -

    correct, thanks Professor.

  • physics -

    so what is the answer???

  • physics -

    √24รท7L

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. Physics

    Can you plz give explaination to the solutions steps by steps in brief?
  2. physics

    A rope of negligible mass passes over a puley of a negligible mass attached to the ceiling. One end of the rope is held by stdent A of mass 70 kg who is at rest on the floor. The opposite end of the rope is held by student B of mass …
  3. Physics Mehanics

    A meter stick is held vertically with one end on the floor and is then allowed to fall. Find the speed of the other end when it hits the floor, assuming that the end on the floor does not slip. (Hint: Consider the stick to be a thin …
  4. physics

    Three identical uniform meter sticks are placed on the floor. The first stick lies along the y axis from y = 0.470 m to y = 1.47 m. The second stick lies along the x axis from x = 0.320 m to x = 1.32 m. The third stick is positioned …
  5. physics

    a one meter chain that weights one newton sits on a flat horizontal table that is one meter from the floor. the coefficient of friction between the chain and the table is 0.15. how much of the chain can dangle off the table until the …
  6. physics

    As shown in the figure below, a stick of length L = 0.330 m and mass m = 0.205 kg is in contact with a rough floor at one end and a frictionless bowling ball (diameter d = 21.50 cm) at some other point such that the angle between the …
  7. physics

    Three identical uniform meter sticks are placed on the floor. The first stick lies along the y axis from y = 0.320 m to y = 1.32 m. The second stick lies along the x axis from x = 0.330 m to x = 1.33 m. The third stick is positioned …
  8. Physics

    A meter-long stick is balanced vertically on the ground. It is then made to fall with a gentle nudge. What is the speed of the end of the stick as it hits the floor?
  9. Physics

    A uniform rod of length L and mass M is held vertically with one end resting on the floor as shown below. When the rod is released, it rotates around its lower end until it hits the floor. Assuming the lower end of the rod does not …
  10. Physics

    A uniform rod of weight 300N and 2m long is hinged to the floor at one end so that it can rotate in the vertical plane. The other end of the rod is tied to a point on the ceiling vertically above the floor hinge by means of a rope …

More Similar Questions