Q.How do u remove a cork from inside a empty bottle of wine without damaging the bottle or cork when the cork is at the bottom of the bottle
A.To get a cork out of an empty wine bottle, take a loop of string, push it in under the cork, pull it tight & pull. It works every time, if done properly.
Q.Does a helium gas canister weigh more wen its full or empty?
A.It would be heavier when full. This is because the helium inside the tank is compressed helium, as compared to the unpressurized air that replaces it.
Q.Is a full fridge more efficient than an empty fridge? What is the maths/physics behind it?
A.Fridges retain their cold temperature more efficiently when full. Each time the door is opened, the cold items inside help the temperature to recover more quickly.