Answer:
A physical matter
Explanation:
A kind of matter with uniform physical properties
The answer you’re looking for is
D. Gamma rays
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Answer:

Explanation:
The rotation rate of the man is:



The resultant rotation rate of the system is computed from the Principle of Angular Momentum Conservation:
![(90\,kg)\cdot (5\,m)^{2}\cdot (0.16\,\frac{rad}{s} ) = [(90\,kg)\cdot (5\,m)^{2}+20000\,kg\cdot m^{2}]\cdot \omega](https://tex.z-dn.net/?f=%2890%5C%2Ckg%29%5Ccdot%20%285%5C%2Cm%29%5E%7B2%7D%5Ccdot%20%280.16%5C%2C%5Cfrac%7Brad%7D%7Bs%7D%20%29%20%3D%20%5B%2890%5C%2Ckg%29%5Ccdot%20%285%5C%2Cm%29%5E%7B2%7D%2B20000%5C%2Ckg%5Ccdot%20m%5E%7B2%7D%5D%5Ccdot%20%5Comega)
The final angular speed is:

Here is my step-by-step-work. Let me know if you have any questions! :)
Answer
This is done by Nuclear Fusion.
Light nuclei like Hydrogen(Deuterium) combine to produce new Elements like Helium.
²H + ²H === ⁴He + ENERGY
The subscripts of the Hydrogen atoms are 1
While that of Helium is 2. My Keyboard couldn't type those