I think metal, steel and copper.
It is a chemical change and a physical change
Answer:
Option D 3.9
Explanation:
First, you need to use the correct equation which is the following:
COP = Q/W
Where:
Q = heat absorbed
W = work done by the pump
COP = coefficient of perfomance
We have all the data, so, all you need to do is replace in the above expression and you shoould get the correct result:
COP = 30 / 7.7
COP = 3.896
This result you can round it to 3.9. option D.
Answer:
14cm
Explanation:
Mass per gram of the piece of wire;
2g of the wire is found in 1m
Since
100cm = 1m;
So;
100cm of the wire contains 2g of the wire
To provide 0.28g
Since;
2g of wire is made up of 100cm
0.28g of wire will be contained in 
= 14cm
14cm of the wire will contain 0.28g
