Brainliest and 100 points to whoever answers these questions

1. explain what it means when we say a substance is magnetic.

2. discuss the relationship between electric and magnetic fields.

3. what role does voltage play in the formation or use of an electromagnet?

4. what is an advantage of using an electromagnet rather than a regular magnet?

Aheat engine running backward is called a refrigerator if its purpose is to extract heat from a cold reservoir. the same engine running backward is called a heat pump if its purpose is to exhaust warm air into the hot reservoir. heat pumps are widely used for home heating. you can think of a heat pump as a refrigerator that is cooling the already cold outdoors and, with its exhaust heat qh, warming the indoors. perhaps this seems a little silly, but consider the following. electricity can be directly used to heat a home by passing an electric current through a heating coil. this is a direct, 100% conversion of work to heat. that is, 19.0 \rm kw of electric power (generated by doing work at the rate 19.0 kj/s at the power plant) produces heat energy inside the home at a rate of 19.0 kj/s. suppose that the neighbor's home has a heat pump with a coefficient of performance of 4.00, a realistic value. note: with a refrigerator, "what you get" is heat removed. but with a heat pump, "what you get" is heat delivered. so the coefficient of performance of a heat pump is k=qh/win. an average price for electricity is about 40 mj per dollar. a furnace or heat pump will run typically 200 hours per month during the winter. what does one month's heating cost in the home with a 16.0 kw electric heater? what does one month's heating cost in the home of a neighbor who uses a heat pump to provide the same amount of heating?

Click the game tab at the bottom of the simulation and select level 1. (there is no seesaw balance for this part of the activity.) balance the first equation, and click check to see if you got it right. if you can’t balance it in the first try, you can try again. work through the five equations for level 1. click continue to go on to level 2, and later level 3. each level is more difficult than the one before. keep trying until all the equations are balanced. in one or two sentences, describe how you did in the balancing game. in a few more sentences, explain one strategy you learned for balancing more complex equations.

Photons with the highest energy have the longest period