General Physics I  
PHYS 121  
   Adventist University
Lawrence E. Turner, Ph.D.
         Home   Syllabus  Schedule  Materials         Labs      Turner  
Remember the Sabbath day to keep it holy. Six days shalt thou labor and do all thy work, but the seventh day is the Sabbath of the LORD thy God.
Exodus 20:8-10  


Lab Activity

ballistic pendulum

This lab activity is to use a ballistic pendulum.

general objectives

  • determine the speed of a projectile
  • use conservation of energy and momentum

concepts and terms

  • conservation of energy
  • gravitational potential energy
  • conservation of momentum
  • inelastic collision


  • presentation
  • obtain experimental data and analyse them
The velocity of a ball impacting a ballistic pendulum with an elastic collision is given by:

v2  =  2 M2 gR(1 − cos θ)

where M is the mass of the pendulum and ball combined, m is the mass of the ball, R is the distance from the pivot to the center of mass of the pendulum and ball, and θ is the angle from the vertical reached by the pendulum when the ball collides with it.

Activity Report  due at the next class period—Wednesday

revised 4 Oct 11  
© 2007–2013, 2014 by Lawrence Turner