Answer:
D) magnetic attraction
Explanation:
Mixture consists of sulfur powder and iron filings . The former is non magnetic and the later is magnetic material . The best way to separate them is to use a magnet . This method is called magnetic separation method . A magnet will attract the iron filling but the sulfur will remain un-attracted . Thus, the two will get separated from each other.
Answer:
Use a lighter string of the same length, under the same tension.
Stretch the string tighter to increase the tension
Explanation:
The wave speed depends on propertices of the medium, not on how you generate the wave. For a string
Increasing the tension or decreasing the linear density (lighter string) will increase the wave speed.
Answer:
Explanation:
2F-F=ma, so F=ma or .17=(13x10-3kg)a then a=13.07m/s2
You oughtta be able to do this one.
The "efficiency" is just the portion of the input work that
comes out in a useful form.
If the efficiency is 70%, that tells you that however much work
you put INto the machine, the machine will do 70% of that much
work for you at the output side.
Put 20,000 J in ... out comes (0.70) x (20,000 J) = 14,000 J .
What happens to the other 30% of the work you put into it ?
It turns into HEAT. That's why machines always have to be
cooled somehow while they're running.
