g This question reviews charges and material properties from early in the semester. (In the notes, this is Week 1 - Charges and Matter.) (a) In any neutral object, there is an equal number of positive and negative charges in the object. there are no charges in that object. there is no way to tell what kind of charges there are in the object. (b) In any conductor, no charges are free to move in the material. electrons are free to move in the material. protons are free to move in the material. electrons and protons are free to move in the material. (c) In any insulator, no charges are free to move in the material. electrons and protons are free to move in the material. electrons are free to move in the material. protons are free to move in the material.

In which situation has the independent variable for the experiment been changed? check all that apply. changed from counting the number of duckweed at day 0 and day 14 to counting them every day changed from testing duckweed growth in beakers to testing duckweed growth in large outdoor tanks changed from testing the effect of ph on duckweed growth to testing the effect of light levels on duckweed growth changed from testing the effect of acid ph on duckweed growth to testing the effect of basic ph on duckweed growth

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.)

Apair of 10μf capacitors in a high-power laser are charged to 1.7 kv.a. what charge is stored in each capacitor? b. how much energy is stored in each capacitor?