To solve this problem we will apply the concepts related to the thermal efficiency given in an engine of the Carnot cycle. Here we know that efficiency is given under the equation
Where,
Temperature of Cold Body
Temperature of Hot Body
= Efficiency
According to the statement our values are:
Replacing we have that
Therefore the temperature of the heat source is 300K
She can climb 0.92 m without losing weight.
<u>Explanation</u>:
Gravitational potential energy is the energy consisting of the product of mass, gravity and height.
1 cal = 4184 J
140 cal = 585760 J
Energy = 585760 J, m = 65.0 kg = 65000 g, Efficiency = 20 %
GPE = mgh
where m represents the mass
g represents the gravity,
h represents the height.
585760 = 65000 
9.8 h
h = 0.92 m.
The lights are wired in PARALLEL.
In fact, when the lights are connected in parallel, they are connected on separate branches to the source of voltage, so if one light bulb burns out, the other lights continue to work because the current continues to flow in the other branches of the circuit.
Vice-versa, if the light bulbs are connected in series, they are on the same branch This means that if one of them burns out, the circuit is open in that point, so the current cannot flow anymore and the other light bulbs turn off as well.
Answer:
Properties of semiconductors are determined by the energy gap between valence and conduction bands. To understand, what is semiconductor, we have to define these terms. In solid-state physics, the energy gap or the band gap is an energy range between valence band and conduction band where electron states are forbidden.
