physics

A ballistic pendulum is used to measure the speed of bullets. It comprises a heavy block of wood of mass M suspended by two long cords. A bullet of mass m is fired into the block in the horizontal direction. The block, with the bullet embedded in it, swings upward (see figure below). The center of mass of the combination rises through a vertical distance h before coming to rest momentarily. In a particular experiment, a bullet of mass 48.0 g is fired into a wooden block of mass 11.2 kg. The block–bullet combination is observed to rise to a maximum height of 19.6 cm above the block's initial height.

(a) What is the initial speed of the bullet?

m/s

(b) What is the fraction of initial kinetic energy lost after the bullet is embedded in the block? (Enter your answer to at least three significant figures.)
(KEm-KEM+m)/KEm=

  1. 👍
  2. 👎
  3. 👁
  1. (a) momentum is conserved ... .0480 Vib = (11.2 + .048) Vbb
    ... (Vbb)^2 = 2 * g * 0.0196

    (b) KEb = 1/2 * 0.0480 * (Vib)^2 ... this is KEm
    ... KEbb = 11.248 * g * 0.0196 ... this is KEM+m

    1. 👍
    2. 👎

Respond to this Question

First Name

Your Response

Similar Questions

  1. Physics

    A 2.50g bullet, traveling at a speed of 425m/s, strikes the wooden block of a ballistic pendulum. The block has a mass of 270g (a) find the speed of the bullet/block combination immediately after the collision (b) how high does

  2. physics

    A ballistic pendulum consists of a 1.25-kg block of wood that is hanging from the ceiling in such a way that when a bullet enters it, the block’s change in height can be recorded as it swings. A bullet having a mass of

  3. Physics

    A student performs a ballistic pendulum experiment using an apparatus similar to that shown in the figure. Initially the bullet is fired at the block while the block is at rest (at its lowest swing point). After the bullet hits

  4. physics

    A 7.0-g bullet is fired into a 1.5-kg ballistic pendulum. The bullet emerges from the block with a speed of 200 m/s, and the block rises to a maximum height of 12.3 cm. Find the initial speed of the bullet?

  1. physics

    in a ballistic pendulum experiment, projectile 1 result in a maximum heigh h of the pendulum equal to 2.6 cm. a second projectile causes the pendulum to swing twice as high, h2=5.2 cm. the second projectile was how many times

  2. Physics

    You have been asked to design a "ballistic spring system" to measure the speed of bullets. A bullet of mass m is fired into a block of mass M. The block, with the embedded bullet, then slides across a frictionless table and

  3. Physics

    A 5.00-g bullet is fired into a 500-g block of wood suspended as a ballistic pendulum. the combined mass swings up to a height of 8.00 cm. What was the magnitude of the momentum of the combined mass immediately after the

  4. dav science

    a machine gun fires 25 g bullets at the rate of 600 bullets per minute with a speed of 200 m/s. calculate the force required to keep the gun in position.

  1. physics

    An observer stands 25 m behind a marksman practicing at a rifle range. The marksman fires the rifle horizontally, the speed of the bullets is 840 m/s, and the air temperature is 20 °C. How far does each bullet travel before the

  2. Physics

    It is well known that bullets and other missiles fired at Superman simply bounce off his chest. Suppose that a gangster sprays Superman's chest with 8 g bullets at the rate of 110 bullets/min, the speed of each bullet being 550

  3. Physics

    A 12.0-g bullet is fired into a 1 100-g block of wood which is suspended as a ballistic pendulum. The combined mass swings up to a height of 8.50 cm. What was the kinetic energy of the combined mass immediately after the

  4. physics

    Ratio of the ranges of the bullets fired from a gun(a constant muzzle speed) at angle x, 2x and 4x is found in the ratio x:2:2 then the values of x will be(assume same muzzle speed of bullets)

You can view more similar questions or ask a new question.