Marshmallow Catapult shooter

 Aim: To make a marshmallow shooter and work out what forces are acting on it.

Equipment: Paper cup, scissors, balloon, marshmallow.

Method:

1. Cut out the bottom of the cup.
2. Cut off the neck of the balloon.
3. Stretch the open end of the balloon over the bottom of the cup.
4. Place marshmallow in cup.
5. Pull balloon back to fire marshmallow.

Results:

Discussion: 

When the marshmallow was in the cup all the forces (thrust, friction, gravity and support) were even as it wasn't moving. When the marshmallow left the cup then the thrust force was greater as it sped up. As it came back down to the ground then gravity and friction/ drag were the greater forces as it slowed down and came back down.

Conclusion:

Yes it worked really well. Some groups taped the balloon to the side of the cup which made it more stable which I would include next time.