You are riding in a school bus. as the bus rounds a flat curve at constant speed, a lunch box with a mass of 0.470 kg suspended from the ceiling of the bus by a string of length 1.75 m is found to hang at rest relative to the bus when the string makes an angle of 30.0 ∘ with the vertical. in this position the lunch box is a distance 49.0 m from the center of curvature of the curve.

Missing question: " What is the speed v of the bus?"

Solution:
Let's solve the problem by writing the equilibrium conditions on both x- and y- axis:


where  is the weight of the lunch box,  is the centripetal force, T is the tension of the string and .

The radius r is the one with respect to the vertical position of the string, therefore
.

From the first equation we find

and if we replace this into the second one, we find

from which we can find the velocity:

The answer is water molecules are split.cellular respiration and photosynthesis are complement  reactions to each other. these are reverse reactions. in cellular respiration glucose and oxygen yield water and carbon dioxide. so, when respiration begins,  glucose molecules are split. in the opposite reaction - in photosynthesis, carbon dioxide and water yield glucose and oxygen. thus,  when respiration begins, water molecules are split.