Physics

posted by .

A bullet mass 10 g strikes a log with a mass of 25 g suspended from a 3 meter long string. The bullet lodges in the log which swings up through an angle of 30 degrees. Find the speed of the bullet just before it hit the log.

  • Physics -

    The law of conservation of linear momentum
    m•v = (m +M) •u.
    v =(m +M) •u/m.
    The law of conservation of energy
    KE =PE,
    (m+M) •u^2/2 =(m+M) • g•h,
    u = sqrt (2•g•h).
    Since h =L(1-cosα) ,
    v =[(m +M) /m] • sqrt[2•g•L(1-cosα)].

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. physics

    A ballistic pendulum, as shown in the figure, was a device used in the past century to measure the speed of bullets. The pendulum consists of a large block of wood suspended from long wires. Initially, the pendulum is at rest. The …
  2. emergency physics

    A 15 g bullet strikes and embeds in a 2.8 kg block suspended at the end of a 1 m string. After the collision the string rises to a maximum angle of 20 degrees to the vertical. what is the speed of bullet?
  3. physics

    The ballistic pendulum is a device used to measure the speed of a fast-moving projectile such as a bullet. The bullet is fired into a large block of wood suspended from some light wires. The bullet is stopped by the block, and the …
  4. Physics

    A ballistic pendulum was a device used in the past century to measure the speed of bullets. The pendulum consists of a large block of wood suspended from long wires. Initially, the pendulum is at rest. The bullet strikes the block …
  5. physics

    A ballistics pendulum is a device used to measure the speed of a fast moving projectile such as a bullet. A bullet of mass 5g is fired into a large block of wood of mass 1.5kg suspended from some light wires. The bullet is stopped …
  6. Physics

    A small wooden block with mass 0.800kg is suspended from the lower end of a light cord that is 1.52m long. The block is initially at rest. A bullet with mass 0.0126kg is fired at the block with a horizontal velocity v0. The bullet …
  7. physics

    As shown in the diagram, a bullet of mass 7.0 g strikes a block of wood of mass 2.1 kg. The block of wood is suspended by a string of length 2.0 m, forming a pendulum. The bullet lodges in the wood, and together they swing upward a …
  8. HELP PHYSICS PLS :)

    A 15 g bullet strikes and embeds in a 2.1 kg block suspended at the end of a 1.2 m string. After the collision the string rises to a maximum angle of 22 degrees to the vertical. what is the speed of bullet?
  9. Mechanics

    Please help me A 15 g bullet strikes and embeds in a 3 kg block suspended at the end of a 1.1 m string. After the collision the string rises to a maximum angle of 23 degrees to the vertical. Find: a) The speed of the bullet. b) the …
  10. physics

    In an experiment to measure the speed of a bullet, the bullet is red into a piece of plasticine suspended from a rigid support by a light thread. (there is a pendulum and two balls, ball one is completely vertical and the bullet hits …

More Similar Questions