I'm pretty sure that you're talking about an "electromagnet",
and that you actually meant an iron core .
Answer:
25%
Explanation:
500 J out of 2000 J is 25%
Your question seems to be incorrect. Please check below:
What force must the deltoid muscle provide to keep the arm in this position? By what factor does this force exceed the weight of the arm?<span>If you hold your arm outstretched with palm upward, as in (Figure 1) , the force to keep your arm from falling comes from your deltoid muscle. Assume that the arm has mass 4 kg and the distances and angles shown in (Figure 1) .
F=?
F/w= ?
The answer is </span><span>339 N</span><span>
</span>
Answer:
(1) A hot drink cooling to room temperature.
(2) The combustion of natural gas.
Explanation:
The spontaneous process is the process in which there is a release of energy and moves towards lower energy and a more thermodynamically stable energy state. All the natural processes are spontaneous.
There are two processes which are spontaneous in the given question are:
(1) A hot drink cooling to room temperature: In this, there is a decrease in energy and also it is a natural process and we know that all the natural processes are spontaneous.
(2) The combustion of natural gas: The fire is an example of an exothermic reaction. The combustion is a combination of a decrease in energy and an increase in entropy. So, this process occurs spontaneously.
