Answer:
The surface tension is 0.0318 N/m and is sufficiently less than the surface tension of the water.
Solution:
As per the question:
Radius of an alveolus, R = 
Gauge Pressure inside, 
Blood Pressure outside, 
Now,
Change in pressure, 
Since the alveolus is considered to be a spherical shell
The surface tension can be calculated as:


And we know that the surface tension of water is 72.8 mN/m
Thus the surface tension of the alveolus is much lesser as compared to the surface tension of water.
Answer: B. 44.64 g
Explanation:
According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants. The number of atoms of each element has to be same on reactant and product side. Thus chemical equations are balanced.
Mass of reactants = mass of iron + mass of oxygen = mass of iron + 34.7 g
Mass of product = mass of iron oxide = 79.34 g
As Mass of reactants = Mass of product
mass of iron + 34.7 g = 79.34 g
mass of iron = 44.64 g
Thus 44.64 g of iron was used in the reaction
Saludos!
Respuesta:28,64 m/s.
Explicación:Datos:
Altura o distancia recorrida: 40 m
Vo: 6 m/s
Aceleración de la gravedad: 9,81 m/s²
El ejercicio puede ser resuelto facilmente utilizando la siguiente formula, sin embargo es posible realizarlo utilizando formulas diferentes.
Entonces tenemos que:

Es importante saber que al estar lanzando el ladrillo hacia abajo, el sentido del movimiento sigue el sentido de la gravedad, es decir es necesario que tomes el valor de la gravedad como positivo (+) y no negativo (-) como normalmente se usa.
Sustituyendo tenemos que:

Que tengas un buen día!