An oil bath maintained at 50.5°c loses heat to its surroundings at the rate of 4.68 kj/min. its temperature is maintained by an electrically heated coil with a resistance of 60 operated from a 110 v line. a thermoregulator switches the current on and off. what fraction of the time will the current be turned on?

The fraction of time for turn on is 0.3852

Solution:

As per the question:

Temperature at which oil bath is maintained,

Heat loss at rate, q = 4.68 kJ/min

Resistance, R =

Operating Voltage,

Now,

Power that the resistor releases,

The fraction of time for the current to be turned on:

t = 0.3852

chemical energy --> gravitational potential energy --> kinetic energy --> elastic potential energy --> gravitational potential energy

explanation:

when emma starts the hike, the chemical energy stored in her body is used to climb up the mountain, and so she gains gravitational potential energy (because at the end, she will be at a higher height h above the ground). then she goes bungee jumping: as she falls, this gravitational potential energy is converted into kinetic energy (because her speed increases as she falls down), until the point when the rope stretches, and she stops moving. at that moment, all the kinetic energy is converted into elastic potential energy due to the stretching of the rope. then, this energy is released because the rope returns to its natural length, and emma gains a small increase in altitude , so she gains some gravitational potential energy.