An iron ball and an aluminum ball of mass 100 g each are heated to the same temperature and then cooled to a temperature of 20°
c. the heat lost by the iron ball is 3.6 kj. the heat lost by the aluminum ball is 7.2 kj. what does this imply?

Acave rescue team lifts an injured spelunker directly upward and out of a sinkhole by means of a motor-driven cable. the lift is performed in three stages, each requiring a vertical distance of 10.0 m: (a) the initially stationary spelunker is accelerated to a speed of 4.90 m/s; (b) he is then lifted at the constant speed of 4.90 m/s; (c) finally he is decelerated to zero speed. how much work is done on the 68.0 kg rescue by the force lifting him during each stage?

The electric potential a distance r from a small charge is proportional to what power of the distance from the charge? a. r^-1 b. r c. r^-2 d. r^2

Frequency of electromagnetic waves that a radio station is assigned is called