Ballistic Pendulum

A ballistic pendulum is a device in which a projectile is fired into a pendulum, and after firing, the projectile and the pendulum swing together to some final height h. h

The speed of the projectile can be determined by using: The conservation of momentum principle during the collision of the projectile with the pendulum 2) The conservation of energy principle after the collision, h

Use energy conservation after the collision: Example A 10.0 g bullet is fired into a 4.00 kg block which then swings to a height of 0.205 m. Determine the speed of the bullet before the collision. Use energy conservation after the collision: Ep bot + Ek bot = Ep top + Ek top mghbot + ½ mv2bot = mghtop + ½ mv2top 0 J + ½ mv2bot = mghtop + O J ½ mv2 = mgh m = mbullet+mblock v = 2.0055 m/s (speed of block and bullet after the collision)

Use conservation of momentum for the collision: vbullet = 804 m/s

A ballistic pendulum experiment: (metal rod versus watermelon)

A ballistic pendulum experiment: (metal rod versus watermelon) (Out-take)