The reason the velocity we measured was lower than the velocity we predicted is that some of the kinetic energy of the marble was converted to thermal energy during the collision. Also, after the collision, air friction and bending in the pendulum rod converted more kinetic energy into thermal energy. Does this explanation match with the your results

Select the best definition for wavelength. the height of an oscillating electromagnetic wave the rate at which electromagnetic waves oscillate. the distance between two crests of an electromagnetic wave. the oscillations of electric and magnetic fields select the best definition for frequency. the oscillations of electric and magnetic fields. the height of an oscillating electromagnetic wave. the distance between two crests of an electromagnetic wave. the rate at which electromagnetic waves oscillate