1. Describe how a sound wave travels through the ear. 2. Explain how a trumpet produces a sound and how the pitch can be changed. It comes from vibration in the trumpet and to change the pitch you have to adjust the opening in your lips

J. j. thomson’s experiment disproved the theory that an atom

Ain is , is 's of ? 0.62 0.79 1.27 1.50

Auniform electric field exists in the region between two oppositely charged plane parallel plates separated by a distance of 1.60 cm . a proton is released from rest at the surface of the positively charged plate and strikes the surface of the opposite plate in a time interval of 3.20×10-6 s. 1-find the magnitude of the electric field. use 1.60×10-19c for the magnitude of the charge on an electron and 1.67×10-27kg for the mass of a proton 2-find the speed of the proton when it strikes the negatively charged plate