Answer:
Well they could do an experiment
Explanation:
Not do sure, but hope this helps.. chow
The assumption that the cosmic microwave background
is the remnant of the environment at the time of the big bang
or very shortly after it explains very well what we observe now.
So it is the current prevailing theory. "Believe" is not involved.
Answer:
this is an example of Newton's Second Law, acceleration happens when a force acts on a mass.
the force that makes the bicycle move is your foot pushing against the pedal
Answer:
![m_2 = 23 kg](https://tex.z-dn.net/?f=m_2%20%3D%2023%20kg)
Explanation:
As we know that the tension in two strings are
![T_2 = 111 N](https://tex.z-dn.net/?f=T_2%20%3D%20111%20N)
![T_4 = 222 N](https://tex.z-dn.net/?f=T_4%20%3D%20222%20N)
now we have
![F_{net} = ma](https://tex.z-dn.net/?f=F_%7Bnet%7D%20%3D%20ma)
so we can say
![(m_1 + m_2)a = T_2](https://tex.z-dn.net/?f=%28m_1%20%2B%20m_2%29a%20%3D%20T_2)
![(12 + m_2)a = 111](https://tex.z-dn.net/?f=%2812%20%2B%20m_2%29a%20%3D%20111)
also we have
![(m_1 + m_2 + m_3 + m_4) a = T_4](https://tex.z-dn.net/?f=%28m_1%20%2B%20m_2%20%2B%20m_3%20%2B%20m_4%29%20a%20%3D%20T_4)
![(12 + m_2 + 15 + 20) a = 222](https://tex.z-dn.net/?f=%2812%20%2B%20m_2%20%2B%2015%20%2B%2020%29%20a%20%3D%20222)
now divide two equations
![\frac{222}{111} = \frac{47 + m_2}{12 + m_2}](https://tex.z-dn.net/?f=%5Cfrac%7B222%7D%7B111%7D%20%3D%20%5Cfrac%7B47%20%2B%20m_2%7D%7B12%20%2B%20m_2%7D)
![2m_2 + 24 = 47 + m_2](https://tex.z-dn.net/?f=2m_2%20%2B%2024%20%3D%2047%20%2B%20m_2)
![m_2 = 23 kg](https://tex.z-dn.net/?f=m_2%20%3D%2023%20kg)
Because electrons are the only piece of the atom that is outside of the nucleus. the protons and neutrons are inside the nucleus.
then also the electrons itself have the charge to begin with