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

Diego is trying to lift a piano to the second floor of his house. diego uses a pulley system and gives a big lift to the piano.the piano moves upward, then stops, and then it starts to fall to the ground. which list best describes the forces on the piano in the proper order? positive force → balanced force → negative force negative force → balanced force → positive force positive force → unbalanced force → negative force negative force → unbalanced force → positive force