3. Una piedra que se tira verticalmente hacia arriba se mueve según la leys = 64y - 8t^2, si "s" se mide en pies (ft) y t en segundos, hallar:
a) SU posición y velocidad después de dos segundos y después de tres
segundos.
b) ¿Qué altura alcanzará?
c) ¿A qué distancia se moverá al cabo del cuarto segundo?

the law of conservation of mass states that in a chemical reaction, the total mass of reactants is equal to the total mass of products. because atoms are only rearranged in a chemical reaction, there must be the same number of sodium atoms and chlorine atoms in both the reactants and products

i believe you are right for all except the 3rd ( look at sqdancefan his answer is much better)

a gas, having a molecular weight of 13 kg/kmol and a kinematic viscosity of 0.25 cm2/s, flows through a pipe 0.25 m internal diameter and 5 km long at the rate of 0.4 m3/s and is delivered at atmospheric pressure.