Wavelengths and Trapezium clusters, oh my

Halley's comet has an orbital period of 76 years, what is the average distance of Comet Halley from the Sun?

a. 51 AU b. 18 AU c. 114 AU d. 660 AU e. 38 AU

Instructions: On occasion, the notation  = [A, ?] will be a shorthand notation for  . The rectangular coordinates of a point are (5.00, y) and the polar coordinates of this point are (r, 67.4°). What is the value of the polar coordinate r in this case?

A. 1.92 B. 4.62 C. 12.0 D. 13.0 E. More information is needed.

Jennifer hits a stationary 200. gram ball and it leaves the racket at 40. m/s

If time lapse photography shows that the ball was in contact with the racket for 40. ms: (a) What average force was exerted on the racket? (b) What is the ratio of this force to the weight of the ball?

A Boeing-737 airliner has a mass of 30,000 kg. The total area of the wings is 100 m2 . What must be the pressure difference between the top and bottom of the wings to keep the airplane up?

a. 1960 Pa c. 7840 Pa b. 2940 Pa d. 15,700 Pa