How are electromagnetic waves different from mechanical waves? Question 1 options:

Electromagnetic waves travel through water; mechanical waves can only travel through solid matter

Electromagnetic waves need a medium to travel through; mechanical waves do not

Electromagnetic waves are long chains of vibrating molecules; mechanical waves aren't

Electromagnetic waves can travel through empty space; mechanical waves can not

Stion 13 of 20 : select the best answer for the question. 13. if a certain mass of mercury has a volume of 0.002 m3 at a temperature of 20°c, what will be the volume at 50°c? a. 0.002021624 m3 b. 0.004021624 m3 c. 0.000010812 m3 d. 0.002010812 m3

Suppose water is leaking from a tank through a circular hole of area ah at its bottom. when water leaks through a hole, friction and contraction of the stream near the hole reduce the volume of water leaving the tank per second to cah 2gh , where c (0 < c < 1) is an empirical constant. a tank in the form of a right-circular cone standing on end, vertex down, is leaking water through a circular hole in its bottom. (assume the removed apex of the cone is of negligible height and volume.) (a) suppose the tank is 20 feet high and has radius 8 feet and the circular hole has radius 2 inches. the differential equation governing the height h in feet of water leaking from a tank after t seconds is dh dt = − 5 6h3/2 . if the height of the water is initially 8 feet, how long will it take the tank to empty? (round your answer to two decimal places.)

Asubject in a clinical research trial experiences a serious, unanticipated adverse drug experience. how should the investigator proceed, with respect to the irb, after the discovery of the adverse event occurrence? a. do not report the adverse drug experience to the irb since it is a common adverse experience.b. report the adverse drug experience to the irb only if there are several other occurrences.c. report the adverse drug experience as part of the continuing review report.d. report the adverse drug experience in a timely manner, in keeping with the irb's policies and procedures, using the forms or the mechanism provided by the irb.