Are all sound frequencies audible to the human ear? Why or Why not?

Determine the maximum r-value of the polar equation r =3+3 cos 0

Which statement is true if the refractive index of medium a is greater than that of medium b? a. total internal reflection is possible when light travels from air to medium b to medium a. b. total internal reflection is possible when light travels from medium a to medium b. c. total internal reflection is possible when light travels from medium b to medium a. d. total internal reflection is possible when light travels from air to medium a. e. total internal reflection is possible when light travels from air to medium b.

A10-kg isto a of 10 m at aa0.9 kg/m.30 kg of ,at aas10-m .. ( 9.8 m/s2 g.)