Utiliando las leyes de Newton encontraremos que la aceleración de Ana es -1.6 m/s^2.
La segunda ley de Newton dice que:
F = m*a
Fuerza es igual a masa por aceleración.
La tercera ley de Newton dice que cuando dos objetos interactuan, cadan objeto ejerce una fuerza de <u>igual magnitud pero opuesta direccion</u> en el otro.
Ahora veamos como aplicar esto.
Sabemos que la niña empuja al niño, asumamos que con una fuerza F.
Tendremos entonces la ecuación:
F = 20kg*(2m/s^2) = 40N
Y por la tercer ley de Newton, esta misma fuerza (pero en opuesta dirección) se aplica a la niña, entonces tendremos:
-40N = 25kg*a
-40N/25kg = a = -1.6 m/s²
La aceleración con la que retrosede la niña es -1.6 m/s²
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Answer:
B. electrons and protons.
Explanation:
In an electrically neutral atom of any element, there are equal number of protons and electrons in the atom.
Protons are the positively charged particles in an atom.
Electrons are the negatively charged particles within the atom.
When the number of protons and electrons are the same or equal, the atom is neutral.
But when there is an imbalance, an ion results.
Nitrogen accounts for 78% of the atmosphere, oxygen 21% and argon 0.9%. Gases like carbon dioxide, nitrous oxides, methane, and ozone are trace gases that account for about a tenth of one percent of the atmosphere.
Answer:
you must add 50 mL
Explanation:
Hi
KOH is a strong base and by adding 100mL 0.05M you will have an amount of 5 millimol.
NaCN is a base and by adding 50 mL 0,150 M you will have an amount of 7,5 mmol.
HCl is a acid and by adding 200 mL 0,075 M you will have an amount of 15 mmol.
The acid reacts with the bases leaving 2.5 mmol unreacted.
Na3PO4 is a base and by adding 50 mL 0,1 M you will have an amount of 5 mmol.
The 2.5 mmol of acid react with the base PO4 ^ -3 forming a regulatory solution of PO4 ^ -3 and HPO4 ^ -2 of pKa 2.12
5 mmol of acid (HNO3) must be added to obtain a regulatory solution formed by the same amount of HPO4 ^ -2 (2.5 mmol) and H2PO4 ^ -1 (2.5 mmol) with pKa 7.21
Considering a quantity of 5 mmol of HNO3 of concentration 0.1 M, 50 mL must be added.
To calculate the pH of the regulatory solution you should consider pH = pKa × Ca / Cb pH = 7.21 × 2.5 / 2.5 = 7.21 Being in the same solution the volume is the same and can be simplified to achieve a faster calculation.
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