Answer:
The first law of thermodynamics doesn't actually specify that matter can neither be created nor destroyed, but instead that the total amount of energy in a closed system cannot be created nor destroyed (though it can be changed from one form to another).
Explanation:
E=F*d/2 = M*g*d/2 = 25kg * 9.8 N/kg *0.65m / 2 = 79.625J
Answer:
La energía mareomotriz se produce gracias al movimiento generado por las mareas, esta energía es aprovechada por turbinas, las cuales a su vez mueven la mecánica de un alternador que genera energía eléctrica, finalmente este último esta conectado con una central en tierra que distribuye la energía hacia la comunidad.
(a) 0.249 (24.9 %)
The maximum efficiency of a heat engine is given by

where
Tc is the low-temperature reservoir
Th is the high-temperature reservoir
For the engine in this problem,


Therefore the maximum efficiency is

(b-c) 0.221 (22.1 %)
The second steam engine operates using the exhaust of the first. So we have:
is the high-temperature reservoir
is the low-temperature reservoir
If we apply again the formula of the efficiency

The maximum efficiency of the second engine is
