The washer and dryer is in the kitchen as there is no where else to put it. It vibrates the floor.?

The spin cycle causes bad vibration and knocks things off the wall in the room behind it. It also travels a few inches, and causes the stove next to it to vibrate also. When we walk across the floor, things in the china hutch, on the t.v. etc., jiggle. Is this a support beam problem under the house, or a problem with too little nailing of the floor plywood? How can I fix it?