Answer:
The tension in the string is
.
Explanation:
For a string with tension
and linear density
carrying a transverse wave at speed
it is true that

solving for
we get:

Now, the transverse wave covers the distance of 7.4mm in 0.88s, which means it's speed is

And it's linear density (mass per unit length) is

Therefore, the tension in the cord is

or in micro newtons

Series Circuit
A series circuit there is only one path for the electrons to flow (see image of series circuit). The main disadvantage of a series circuit is that if there is a break in the circuit the entire circuit is open and no current will flow. An example of a series would the the lights on many inexpensive Christmas trees. If one light goes out all of them will.
Parallel Circuit
In a parallel circuit the different parts of the electric circuit are on several different branches. There are several different paths that electrons can flow. If there is a break in one branch of the circuit electrons can still flow in other branches (see image of parallel circuit). Your home is wired in a parallel circuit so if one light bulb goes out the other will stay on.
HOPE THIS HELPS YOU MATE!!
I HAVE ALSO GIVEN THE EXPLANATION THINKING THAT IT MIGHT HELP YOU.
THANK YOU.
Answer:
15 m/s
Explanation:
Speed(m/s) = distance(m)/time(s)
distance = 216 km = 216,000 m
time = 4 hours = 14,400 s
speed = 216000/14400 = 15 m/s