Answer:
m = 0.0125 kg
Explanation:
Let us apply the formula for the speed of a wave on a string that is under tension:

where F = tension force
μ = mass per unit length
Mass per unit length is given as:
μ = m / l
where m = mass of the string
l = length of the string
This implies that:

Let us make mass, m, the subject of the formula:

From the question:
F = 20 N
l = 4.50 m
v = 85 m/s
Therefore:

Answer:
Say a 14 year old girl was at a construction site and she was asked to move something like a 10,000 pound brick( one brick). She would be acting on it as the unbalanced force but they would still not change their position.
so to say the girl would be doing everything she could to move that brick but the brick would still be in that same spot so the unbalanced force (the girl) would be acting on the thing that was at rest but it wouldn't move.
so the unbalanced force would not really be acting on the thing at rest; even though the unbalanced force was doing something to the brick.
( just think about it and you will eventually get it...just imagine in your head...)
Explanation:
Answer:
The doorbell transforms electrical energy into sound.
Explanation:
The doorbell MAY turn electrical energy into motion of a striker which then impacts a resonator creating sound. However all door bells do not have solenoids. Some are electronic playing recordings when activated.
All doorbells do produce sound, though.