3-2-1 We have lift off! HS physics students launched 2-liter bottle rockets to demonstrate the concept of conservation of momentum and equal impulse. The launches started with simple air pressure alone, then a small amount of water was added so students could see the impact of increasing mass on the propellant. A final test increased the amount of air pressure with the water. What a great lesson! Maybe some future NASA scientists here! #TKSTRONG | TK Schools