Unit 1: Science and Engineering: Quiz 1.2: Question 1: Which action describes an experimental investigation?
A: Exploring the relationship of the material in a rock sample and its hardness
Question 2: How did creativity help John in this experiment?
C: It helped him use materials in a new way to help him gather data
Question 3: Which statement is a hypothesis/
A: If the temperature increases, then crickets will chirp more
Question 4: A student investigated the factors that affect math grades. Which statement from the lab report best represents a conclusion for this investigation?
A: When students spend too much time studying math, their grades in other subjects will be lower
Question 5: What are two constants in this experiment?
B: The kind of containers used
C: The number of crickets in each containers

Find the vertex(use the completing the square method), findthe x- and y-intercepts, and sketch the graph offunction. y = 2x2 + 4x - 1

15. give an example for some particles or waves that are moving faster than light in everyday life 16. what is a laser? 17. what is an oscilloscope? 18. what does it means practically that nothing is faster than light in vacuum? 19. what is vacuum?

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.)