f990dc30_ion__and_Energy__Build_a_Blimp__Explain
[Steps] Students will propel the blimp using a propulsion system made with a straw and latex balloon. Slip one end of the straw into the balloon. Tape the balloon to the straw using duct tape. [Explain] 
Your balloon needs a something to propel it forward. Ask and discuss: What are your ideas for propelling your blimp forward? Students share their ideas. You will use a straw and latex balloon for your propulsion system. Slip one end of the straw into the balloon. Tape the balloon to the straw using duct tape.
Force, Motion, and Energy: Build a Blimp
Explain