Why does sandpaper get hot when it is rubbed against rusty metal?

In the sport of parasailing, a person is attached to a rope being pulled by a boat while hanging from a parachute-like sail. a rider is towed at a constant speed by a rope that is at an angle of 15 ∘ from horizontal. the tension in the rope is 1900 n. the force of the sail on the rider is 30∘ from horizontal. what is the weight of the rider? express your answer with the appropriate units.

Infrared rays have a shorter wavelength than question 11 options: x-rays. ultraviolet rays. radio waves. gamma rays.

Explain the comparisons between nature and packingtown that appears on pages 81 and 82 answer