What is the effect of changing pipe length on the frequency? What is the effect of changing pipe diameter on the frequency? What is the effect of changing the exhaling force on the frequency? What are...What is the effect of changing pipe length on the frequency? What is the effect of changing pipe diameter on the frequency? What is the effect of changing the exhaling force on the frequency? What are the some of the possible sources of experimental error in this exercise and how might they be reduced?