Answer: The correct answer is option (B).
Explanation:
Law of conservation of mass: 'In a chemical reaction, mass neither be created nor be destroyed'
In the balance chemical equation,total mass of the reactants is equal to the total mass of the products.
A. 
![[2\times (23 g/mol)+(35.5 g/mol)\times 2]=[23 g/mol+35.5 g/mol]](https://tex.z-dn.net/?f=%5B2%5Ctimes%20%2823%20g%2Fmol%29%2B%2835.5%20g%2Fmol%29%5Ctimes%202%5D%3D%5B23%20g%2Fmol%2B35.5%20g%2Fmol%5D)
117 g/mol ≠ 58.5 g/mol
Law of Conservation of Mass not followed.
B.
![[2\times (23 g/mol)+(35.5 g/mol)\times 2]=2\times [23 g/mol+35.5 g/mol]](https://tex.z-dn.net/?f=%5B2%5Ctimes%20%2823%20g%2Fmol%29%2B%2835.5%20g%2Fmol%29%5Ctimes%202%5D%3D2%5Ctimes%20%5B23%20g%2Fmol%2B35.5%20g%2Fmol%5D)
117 g/mol = 117 g/mol
Law of Conservation of Mass is followed.
C.
![[2\times (23 g/mol)+(35.5 g/mol)\times 2]=2\times [23 g/mol+35.5 g/mol]](https://tex.z-dn.net/?f=%5B2%5Ctimes%20%2823%20g%2Fmol%29%2B%2835.5%20g%2Fmol%29%5Ctimes%202%5D%3D2%5Ctimes%20%5B23%20g%2Fmol%2B35.5%20g%2Fmol%5D)
188 g/mol ≠ 117 g/mol
Law of Conservation of Mass not followed.
D.
![[(23 g/mol)+(35.5 g/mol)\times 2]=2\times [23 g/mol+35.5 g/mol]](https://tex.z-dn.net/?f=%5B%2823%20g%2Fmol%29%2B%2835.5%20g%2Fmol%29%5Ctimes%202%5D%3D2%5Ctimes%20%5B23%20g%2Fmol%2B35.5%20g%2Fmol%5D)
94 g/mol ≠ 117 g/mol
Law of Conservation of Mass not followed.
Hence, the correct answer is option (B).
We can use kinematics here if we assume a constant acceleration (not realistic, but they want a single value answer, so it's implied). We know final velocity, vf, is 1.0 m/s, and we cover a distance, d, of 0.47mm or 0.00047 m (1m = 1000mm for conversion). We also can assume that the flea's initial velocity, vi, is 0 at the beginning of its jump. Using the equation vf^2 = vi^2 + 2ad, we can solve for our acceleration, a. Like so: a = (vf^2 - vi^2)/2d = (1.0^2 - 0^2)/(2*0.00047) = 1,064 m/s^2, not bad for a flea!
If a boat is going East at 15mph and there is a water current going southeast at 45° then the boat is being drifted southward. So since the current is going at an angle then it has a x and y component. So Rx refers to the x-component force of the current and Ry refers to the y-component of the current, and |R| refers to the magnitude of these forces.