Aresearcher finds that white bread contains more preservatives and has a higher moisture content than wheat bread. she designs a test to determine whether the type of bread, white or wheat, affects the amount of mold growth. what must be done for the researcher to accurately measure the dependent variable?

a. she will need to allow mold to grow for more days on the white bread, since it contains more preservatives, to measure the dependent variable.
b. she will need to limit the dependent variable to white bread or wheat bread.
c. she will need to allow mold to grow for fewer days on the white bread, since it contains more preservatives, to measure the dependent variable.
d. she will need to learn out how to quantitatively measure mold growth to measure the dependent variable.

(i put 99 points on this; and you'll receive brainliest).

If the speed of a particle triples ,by what factor does its kinetic energy increase?

Astudent throws a water balloon with speed v0 from a height h = 1.76 m at an angle θ = 21° above the horizontal toward a target on the ground. the target is located a horizontal distance d = 9.5 m from the student’s feet. assume that the balloon moves without air resistance. use a cartesian coordinate system with the origin at the balloon's initial position. (a) what is the position vector, rtarge t, that originates from the balloon's original position and terminates at the target? put this in terms of h and d, and represent it as a vector using i and j. (b) in terms of the variables in the problem, determine the time, t, after the launch it takes the balloon to reach the target. your answer should not include h. (c) create an expression for the balloon's vertical position as a function of time, y(t), in terms of t, vo, g, and θ. (d) determine the magnitude of the balloon's initial velocity, v0, in meters per second, by eliminating t from the previous two expressions.

Two loudspeakers, 5.5 m apart and facing each other, play identical sounds of the same frequency. you stand halfway between them, where there is a maximum of sound intensity. moving from this point toward one of the speakers, you encounter a minimum of sound intensity when you have moved 0.33 m . assume the speed of sound is 340 m/s.part a) what is the frequency of the sound? part b) if the frequency is then increased while you remain 0.21 m from the center, what is the first frequency for which that location will be a maximum of sound intensity? express your answer to two significant figures and include the appropriate units.