Strictly speaking, as more and more skyscrapers are built on the surface of the Earth, does
the day tend to become longer or shorter?
And strictly speaking, does the falling of autumn leaves tend to lengthen or shorten the
24-hour day? What physical principle supports your answers?
1. lengthen; shorten; conservation of angular
momentum
2. lengthen; shorten; conservation of kinetic
energy
3. shorten; lengthen; conservation of angular
torque
4. shorten; lengthen; conservation of inertia