What are the velocities of sound waves in air, helium, and carbon dioxide? Show your data. Which was the fastest? Why do sound waves travel at different speeds in each gas? Explain. Note that the values for helium will be incomplete in these frequency ranges.

How does the image distance (di) of a convex lens compare with the image distance of a concave lens? a. the image distance of the convex lens is positive, and that of the concave lens is negative. b. both are negative for a virtual image. c. both are positive for a virtual image d. the image distance of the convex lens is negative, and that of the concave lens is positive.

In positive numbers less than 1, the zeros between the decimal point and non zero are significant

Oxygen undergoes an isentropic expansion from 120 degree c and 280 kpa absolute to 140 kpa absolute. determine the final temperature of the oxygen and the amount of work per kg of o_2 produced in the process if it is adiabatic.