M = mass of aluminium = 1.11 kg
= specific heat of aluminium = 900
= initial temperature of aluminium = 78.3 c
m = mass of water = 0.210 kg
= specific heat of water = 4186
= initial temperature of water = 15 c
T = final equilibrium temperature = ?
using conservation of heat
Heat lost by aluminium = heat gained by water
M ( - T) = m (T - )
(1.11) (900) (78.3 - T) = (0.210) (4186) (T - 15)
T = 48.7 c
Answer:
C. The change of internal energy of a system is the sum of work and heat spent on it.
Explanation:
The law of conservation of Energy states that energy cannot be destroyed but can only be converted or transformed from one form to another. Therefore, the sum of the initial kinetic energy and potential energy is equal to the sum of the final kinetic energy and potential energy.
Mathematically, it is given by the formula;
Ki + Ui = Kf + Uf .......equation 1
Where;
Ki and Kf are the initial and final kinetic energy respectively.
Ui and Uf are the initial and final potential energy respectively.
The law of conservation of Energy is another way to describe the law of Thermodynamics. It states that the change of internal energy of a system is the sum of work and heat spent on it.
Mathematically, it is given by the formula;
ΔU = Q − W
Where;
ΔU represents the change in internal energy of a system.
Q represents the net heat transfer in and out of the system.
W represents the sum of work (net work) done on or by the system.
Development of the Embryo. The next stage in development is the embryo, which develops within the amniotic sac, under the lining of the uterus on one side. This stage is characterized by the formation of most internal organs and external body structures.
Answer:
Lamentablemente el problema está incompleto, pues no sabemos la dirección en la que se aplican las fuerzas. Por ello, voy a resolver el problema asumiendo dos casos. (abajo se puede ver una imagen donde se describe cada caso)
1) Todas las fuerzas están en la misma dirección.
Entonces la fuerza neta será la suma de las 3 fuerzas, entonces:
F = 48N + 60N + 30N = 138N
Y por la segunda ley de Newton sabemos que:
F = m*a
fuerza igual a masa por aceleración.
Entonces la aceleración está dada por:
a = F/m = 138N/12kg = 11.5 m/s^2
2) Segundo caso, suponemos que F1 es opuesta a F2 y F3
En este caso, la fuerza neta será:
F = F2 + F3 - F1 = 60N + 30N - 48N = 42N
En este caso, la aceleración será:
a = 42N/12kg = 3.5 m/s^2
