Answer:
The kinetic energy of the phone would increase. The gravitational potential energy of the phone would decrease.
Explanation:
The kinetic energy 
of an object is proportional to the square of the speed of that object. If air resistance is negligible, the phone would accelerate under gravitational pull and speed up. Hence, the kinetic energy of the phone would increase.
The gravitational field near the surface of the earth is approximately constant. Hence, the gravitational potential energy 
of the phone would be proportional to its height. As the phone approaches the ground, the height of the phone becomes lower and the gravitational potential energy of the phone would decrease.
When smoke particles pass between the source of radiation and the detector the drop in radiation will be sufficient to tigger the alarm. <span />
Answer:
U = 102.8 J (100 J to two significant digits)
Explanation:
potential energy converted = 20(9.8)(1.8) = 352.8 J
kinetic energy at base of track = ½(20)5.0² = 250 J
energy (work) of friction 352.8 - 250 = 102.8 J
Aerobic dance<span> has its foundation in </span>dance<span>-inspired movements. It is a cardiovascular workout set to music in a group </span>exercise<span> setting. You do not have to memorize </span>dance<span> moves, as the classes are taught by instructors who verbally tell and visually show the </span>choreography<span>.</span>
