Select all that apply.
a column of air in a tube is vibrating at its fundamental frequency of 150hz. which of the following frequencies could also exist in the tube as harmonics?
- 75 hz
- 225 hz
- 300 hz
- 450 hz

Abug is 12 cm from the center of a turntable that is rotating with a frequency of 45 rev/min . what minimum coefficient friction is required so that the bug stays on the turntable?

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

Hi , i am new here can anyone me out with this question why is space black after having so many shining objects like sun , moon , stars