20. Reduction of one's ability to exercise or perform work begins at the high altitude of a. 3, 0 feet above sea level.
b. 3,500 feet above sea level.
C. 4,000 feet above sea level.
d. 5,000 feet above sea level.

In a heat engine if 1000 j of heat enters the system the piston does 500 j of work, what is the final internal energy of the system if the initial energy was 2000 j ?

Asher cycles 12 miles in 16 hours. what is his speed?

At 20∘c, the hole in an aluminum ring is 2.800 cm in diameter. you need to slip this ring over a steel shaft that has a room-temperature diameter of 2.804 cm . 1. to what common temperature should the ring and the shaft be heated so that the ring will just fit onto the shaft? coefficients of linear thermal expansion of steel and aluminum are 12×10−6 k−1 and23×10−6 k−1 respectively.