stuck in room under barn -1 reply

I have played ALL the HL games..including HL1, HL2 E1, and now HL2E2. now I'm stuck again...I drove the car,got to the red roof barn and we went in...jumped down under the floor boards and came out in a big room with a machine and dead Advisor. Alyx pulled him away from the machine and pushed some buttons to start it up... big tube popped up with ball bouncing around in it..now im stuck there. I dont know what to do..been pushing pulling everything around there.

You shoot the gravity gun at the ball and it should get the ball out of there.