A. both permanent magnets and electromagnets.
Explanation:
A permanent magnet can affect and attract any other permanent magnet and even electromagnet.
They also affect any magnetic materials especially metals that can be magnetized.
In the vicinity of such substances, an attractive or repulsive force sets in and they both interact in the presence of the force field in place.
Permanent magnets cannot magnetize non-magnets.
An electromagnet is a magnet produced by the passage of electric current through a wire wound round a metallic core.
learn more:
Electromagnet brainly.com/question/2191993
#learnwithBrainly
Answer:
Mg ²⁺
Explanation:
Τhe metal loses electrons and in forming Mg²⁺ ,it loses 2 electrons and hence oxidized.
Mg(s) ⇒ Mg²⁺ + 2e⁻
Hello, to answer your question. It is because all machines require a fuel or source to power it making it imperfect for using some source that may not be renewable.
Signed by, Virtouso Sargedog
Answer:

Explanation:
We are asked to find the mass of a sample of metal. We are given temperatures, specific heat, and joules of heat, so we will use the following formula.

The heat added is 4500.0 Joules. The mass of the sample is unknown. The specific heat is 0.4494 Joules per gram degree Celsius. The difference in temperature is found by subtracting the initial temperature from the final temperature.
- ΔT= final temperature - initial temperature
The sample was heated <em>from </em> 58.8 degrees Celsius to 88.9 degrees Celsius.
- ΔT= 88.9 °C - 58.8 °C = 30.1 °C
Now we know three variables:
- Q= 4500.0 J
- c= 0.4494 J/g°C
- ΔT = 30.1 °C
Substitute these values into the formula.

Multiply on the right side of the equation. The units of degrees Celsius cancel.

We are solving for the mass, so we must isolate the variable m. It is being multiplied by 13.52694 Joules per gram. The inverse operation of multiplication is division, so we divide both sides by 13.52694 J/g

The units of Joules cancel.


The original measurements have 5,4, and 3 significant figures. Our answer must have the least number or 3. For the number we found, that is the ones place. The 6 in the tenth place tells us to round the 2 up to a 3.

The mass of the sample of metal is approximately <u>333 grams.</u>