Summarize the physical reasons that sound waves travel at different speeds through different mediums

Which material produces static charge when rubbed?

Avery hard rubber ball (m = 0.5 kg) is falling vertically at 4 m/s just before it bounces on the floor. the ball rebounds back at essentially the same speed. if the collision with the floor lasts 0.05 s, what is the average force exerted by the floor on the ball?

Use the right-hand rule for magnetic force to determine the charge on the moving particle. this is a charge.