Circus Lights 
learning-center.homesciencetools.com/article/circus-science/

​Build a Paper Roller Coaster 
www.sciencebuddies.org/stem-activities/paper-roller-coaster?from=Blog

Circus-Trick Science:  How to Balance Anything 
www.sciencebuddies.org/stem-activities/balance-marshmallows?from=Blog