Question

An inventor claims to have developed a resistance heater that supplies 1.2 kWh of energy to a room for each kWh of electricity it consumes. Is this a reasonable claim, or is it true that the inventor has developed a perpetual-motion machine

Answer 1

Answer:

if we are to go by the first law of thermodynamics, the Inventors claims are not reasonable.

The inventor has developed a perpetual-motion machine { any device that violates the first law of thermodynamics}

Explanation:

Given that;

energy supplied to a room Qh= 1.2 kWh

for each for each kWh of electricity it consumes, i.e work input W = 1 kWh

W know that; the first law of thermodynamics says energy can neither be created nor destroyed but can flow from one body to another;

which means ∑Q should or must be equal to ∑W;  ∑Q = ∑W

but in the given system; Qh⇒1.2 kWh is NOT equal to W⇒1 kWh

i.e Qh⇒1.2 kWh ≠ W⇒1 kWh

which simply means his device create energy and that violate the first law of thermodynamics.

Therefore, if we are to go by the first law of thermodynamics, the Inventors claims are not reasonable.

The inventor has developed a perpetual-motion machine { any device that violates the first law of thermodynamics}