We were told to make our own project, i chose to base mine on the conservation of momentum and used the pendulum. Though im kind of stuck, i need more things to write about and more equations i can calculate using the pedulum. all i have so far is E=mgh H1=0.145m (90dgrs) M=0.045kg E=0.045x9.8x0.145 E=0.063945 J 1/m(v^2) v^2=0.063945x2/0.045 v=1.685ms^-2 so thats the velocity of my first ball on 90 degrees. and when that ball hit the ball on the other side went up 0.11m (11cm) so; H2=0.11 m=0.045 done same equations as before and got v=1.468ms^-2 so now i can only prove that the velocity changes to 1.468 from 1.685. and that its inelastic because it changes, if you know what i mean. i need more things that i can work with, more things i can try and find out with the pendulum. and how can i find out how long it will take before the pendulum will come to rest. help anyone?