Answer: Can I get a picture???
Frequency of a sound wave is commonly referred to as pitch. That is the specialized name for frequency of a sound wave.
Just remember it as pitch.
Answer:
Yes the frequency of the angular simple harmonic motion (SHM) of the balance wheel increases three times if the dimensions of the balance wheel reduced to one-third of original dimensions.
Explanation:
Considering the complete question attached in figure below.
Time period for balance wheel is:


m = mass of balance wheel
R = radius of balance wheel.
Angular frequency is related to Time period as:

As dimensions of new balance wheel are one-third of their original values


Answer:
b. passes through the principal focal point.
Explanation:
Light wave can be defined as an electromagnetic wave that do not require a medium of propagation for it to travel through a vacuum of space where no particles exist.
A lens can be defined as a transparent optical instrument that refracts rays of light to produce a real image.
Basically, there are two (2) main types of lens and these includes;
I. Diverging (concave) lens.
II. Converging (convex) lens.
A converging lens refers to a type of lens that typically causes parallel rays of light with respect to its principal axis to come to a focus (converge) and form a real image. This type of lens is usually thin at the lower and upper edges and thick across the middle.
For a converging lens, a ray arriving parallel to the optic axis passes through the principal focal point.
Answer:
Kilogram(kg) is the SI unit for mass while kilometre(km) is a unit for length. They are both similar in that they are 10^3 of a unit, thus kilo. As kilogram represents mass, it is a measure of how much matter is present in an object. While kilometre is a measure of distance/how long or short an object is.