The manufacturer of a 9[V] flashlight battery says that the battery will deliver 20[mA] for 80 continuous hours. However, during that time the voltage will drop from 9[V] to 6[V]. Assume the voltage change with time is linear in time; in other words, the plot of voltage versus time is a straight line. Assume that the current is constant during these 80 hours.

Your question should includes how much energy does the battery deliver in 80 hours interval.

The battery delivers 17,280 J

Explanation:

Starting voltage v1 = 9V

Final voltage v2 = 6V = voltage drop after 80hrs

v = v1 - v2 = 9 - 6 = 3V

Electrical current (i) = 20[mA] = 20*10^-3 A

Discharging time = 80 Hrs = 80*(60*60) sec = 288,000 sec

Work done = energy (W) = p.t

Where p = v*i

W = v*i*t

W = 3*(20*10^-3)*288,000

W = 17,280 J

The battery delivers 17,280 J

.) the observation by semmelweis that more mothers died of childbed fever when their doctors also worked in the morgue

report!

explanation:

physics means: "the branch of science concerned with the nature and properties of matter and energy. the subject matter of physics, distinguished from that of chemistry and biology, includes mechanics, heat, light and other radiation, sound, electricity, magnetism, and the structure of atoms."