lf a heavy point mass is suspended by a weightless, inextensible and perfectly flexible string from a rigid support, then this arrangement is called simple pendulum.
In practice, however, these requirements cannot be fulfilled. So we use a practical pendulum.
A practical pendulum consists of a small metallic solid sphere suspended by a fine silk thread from a rigid support. This is the practical simple pendulum which is nearest to the ideal simple pendulum.
Note :
The metallic sphere is called the bob.
When the bob is displaced slightly to one side from its mean position and released, it oscillates about its mean position in a vertical plane.
Answer:
<h2>1. Friction is A. a force</h2>
<h2>2. An unbalanced force is B. When the object moves and accelerates</h2>
If she has a choice and the wiring details are stated on the packaging,
then Janelle should look for lights that are wired in parallel within the
string, and she should avoid lights that are wired in series within the string.
If a single light in a parallel string fails, then only that one goes out.
The rest of the lights in the string continue to shimmer and glimmer.
If a single light in a series string fails, then ALL of the lights in that string
go out, and it's a substantial engineering challenge to determine which light
actually failed.
67.8 turns needed by the secondary coil to run the bulb.
<u>Explanation</u>:
We know that,
For calculating number of turns
Given that,
We need to find the number of turns in the secondary winding 
to run the bulb at 120W 
Firstly find the secondary voltage in the transformer use,
Now, finding the number of turns in secondary coil. Use,
The number of turns in the secondary winding are 67.8 turns.
F should be 10. If The Whole top is 50cm, then we should subtract 10n and 30n which gives us 10.
Or it could be 15 if both top and bottom are 25. 10+15= 25.
