Halo salam kenal....
Bingung juga mau tulis di matematika atw fisika....
Menurut kalian ada ngga konsep matematika yg ngga punya makna fisis di dunia nyata?

sepengetahuan saya tidak ada, matematika digunakan untuk mempermudah perhitungan dan membantu perhitungan konsep2 ilmu lain seperti ilmu statistik, probabilitas, diferrensial, exponensial, dsb. jadi perhitungan secara matematis jelas berbeda dengan perhitungan secara fisis yang menentukan fenomena2 fisis dari suatu value yang kita dapat.

Nina? Oh.... bgt...
Sptnya bilangan imajiner...
Tapi ngga juga, impedansi kapasitor bil.imajiner..... Apa ya?

Bilangan imajiner dan/atau bilangan kompleks ini sering dipakai di bidang teknik elektro dan elektronika untuk menggambarkan sifat arus AC (listrik arus bolak-balik) atau untuk menganalisa gelombang fisika yang menjalar ke arah sumbu tertentu.

Dalam wiki bahasa Inggris penjelasan lebih lanjut sbb:

Applications of imaginary numbers

For most human tasks, real numbers (or even rational numbers or integers) offer an adequate description of data. For instance, fractions such as ⅔ and ⅛ would be meaningless to a person counting stones, but essential to a person comparing the sizes of different collections of stones. In the same way, negative numbers such as –3 and –5 would be meaningless when measuring the mass of an object, but essential when keeping track of monetary debits and credits.[2] Similarly, imaginary numbers have essential concrete applications in a variety of scientific and related areas such as signal processing, control theory, electromagnetism, fluid dynamics, quantum mechanics, cartography, and vibration analysis.
In electrical engineering, for example, the voltage produced by a battery is characterized by one real number called potential (e.g. +12 volts or –12 volts), but the alternating current (AC) voltage in a home requires two parameters — potential and an angle called phase. The AC voltage is, therefore, said to have two dimensions. A two dimensional quantity can be represented mathematically as either a vector or as a complex number (known in the engineering context as phasor). In the vector representation, the rectangular coordinates are typically referred to simply as x and y. But in the complex number representation, the same components are referred to as real and imaginary. When the complex number is purely imaginary, such as a real part of 0 and an imaginary part of 120, it means the voltage has a potential of 120 volts and a phase of 90°, which is, physically speaking, very much a real voltage.

analog dengan relasi matematika-ke-fisika, juga fisika-ke-engineering.
tidak semua teori fisika memiliki aplikasi di engineering.
kasusnya mirip, ada yang teorinya dulu muncul kemudian aplikasinya, misal konsep spin elektron (setelah bertahun2 barulah muncul aplikasi berdasar sifat ini);
ada juga teori fisika yang di-develop karena kebutuhan aplikasi, (mungkin lebih jarang) misal fisika nuklir (saat era perang dunia ke-2).