I should think that Yolanda should use litmus paper throughout the reaction as its color will tell when the mixture is neutral and therefore then, when she can stop adding either the hydrochloric acid or the sodium hydroxide or if one or the other needs to be added to make the solution approach neutral. Blue litmus paper stays blue in a neutral solution, but will turn red in an acidic solution.
Answer:
A) - 1.8 m/s
Explanation:
As we know that whole system is initially at rest and there is no external force on this system
So total momentum of the system must be conserved
so we will have

now plug in all data into above equation



so correct answer is
A) - 1.8 m/s
Matter, substance. Material howya call it.
Answer: Because temperature is a measure of the average kinetic energy of the atoms or molecules in the system. The zeroth law of thermodynamics says that no heat is transferred between two objects in thermal equilibrium; therefore, they are the same temperature.
Explanation:9 (- _ -)
Answer:
a) Due to the characteristic that a converging lens focuses light rays from infinity and parallel to its main axis. Therefore, the lens should be placed at a distance "f" from the film, in this way it will form the image of the object placed at infinity in said film.
b) Since the converging lens produces an image of an object placed at a distance of 2f, the lens must be placed at the same distance (2f), so that this object that is placed at a distance of 2f is focused.
Explanation: