Final answer:
To find the time a surgical cauterizer needs to perform the ablation of a malignant lesion, it's essential to calculate the total energy needed to heat and boil the tissue water content and then divide this by the power output of the device. Similarly, the power output of an ultrasound imaging device is determined by multiplying its intensity by its emitting surface area.
Step-by-step explanation:
The question at hand is regarding the calculation of time necessary for a surgical cauterizer to raise the temperature of tissue and boil away water during the ablation of a malignant lesion. Since this is a calculation that involves understanding the transfer of energy and changes in temperature, it's essential to use the relationship between power, energy, and time, alongside the specific heat capacity of water and the latent heat of vaporization.
First, we need to find out how much energy is required to raise the temperature of 1.00 g of tissue from 37.0°C to 100°C. We use the specific heat capacity of water (4.18 J/g°C) for this calculation because human tissue is predominantly made of water. Then, we calculate the energy needed to turn 0.500 g of water into steam at 100°C, using the latent heat of vaporization for water (2260 J/g). The sum of these energies will give us the total energy required for the procedure.
The power output of the cauterizer is given by the product of current (I) and voltage (V), so we multiply 2.00 mA (which is 2.00 x 10⁻³ A) by 15.0 kV (which is 15.0 x 10³ V). After finding the power in watts, we can calculate time by dividing the total energy required by the power output of the cauterizer.
As for the ultrasound machine, its power output is calculated by multiplying the intensity (1.50×10² W/m²) by the area of its rectangular head (3.00 cm by 5.00 cm), with the area converted to meters squared. This will yield the total power in watts emitted by the ultrasound machine.