Question

Design a physics problems (with numbers and can be solved) related to electric, circuits, magnetic field, electric field, wave (light, sound, diffraction) and has real world context (chirstmas light, iron, cost of electric bills, rainbow, magnet....). The problem needs to include a background information. The situation is "rich" enough to need a picture drawn. The physics scenario is more challenging that just plugging numbers into one of the equations.

- The problem needs to come from a real world context

- The context involves a motivation for why you want to calculate that specific value.  

- It is reasonable to look up material properties online, but most values needed is in the problem

- (Use knowledge of resistor, current, Ohm's law, parellel/series circuits, energy, power, difraction grating, magnetic, electric field, charge, single slit, double slit, light, sound wave,..)

(EX: You have a great summer job working in a cancer research laboratory. Your team is trying to construct a gas laser that will give off light of an energy that will pass through the skin but be absorbed by cancer tissue. You know that an atom emits a photon (light) when an electron goes from a higher energy orbit to a lower energy orbit. Only certain orbits are allowed in a particular atom. To begin the process, you calculate the energy of photons emitted by a Helium ion in which the electron changes from an orbit with a radius of 0.30 nanometers to another orbit with a radius of 0.20 nanometers. A nanometer is 10-9 m. The helium nucleus consists of two protons and two neutrons. )

Answer 1

You have an air conditioner in your room. The temperature of the locality in that day was 40-degree Celsius. Assume that 26 degree Celsius is the temperature when you have to stop the air conditioner. You also have a fan in the room which consume much lesser electricity than the air conditioner. Also, assume if the temperature of room rise more than 30-degree Celcius you will turn on the AC with fan. You and your brother have two opinions about how to operate the AC most economically. Your brother wants to run the AC at a target temperature 19 degrees Celcius without a fan, and when temperature down to 21 degrees Celcius turn off it and turn on it when it is greater than 26 degree. And you think to turn on the AC with a target temperature 26-degree temperature with fan and turn it off when the temperature is 28 degree and turn it on again when the temperature is higher than 30 degree. Assume that there is no dast in the room to damage the AC. Which approach is more economical and why?