The mass of an atom comes from the protons and neutrons that is found in the nucleus. The number of protons is the atomic number of an element. To find the number of neutrons, subtract the atomic number from the mass of an atom. For example, sodium’s atomic number is 11. This will tell us that sodium has 11 protons in it. The atomic mass of sodium is 23. So subtract 23 form 11 gives us 12. Therefore, there are 12 neutrons in sodium.
Answer:
Though you have not gave the choices, I do believe it is “testing”
Explanation:
Answer:
The average recoil force on the gun during that 0.40 s burst is 45 N.
Explanation:
Mass of each bullet, m = 7.5 g = 0.0075 kg
Speed of the bullet, v = 300 m/s
Time, t = 0.4 s
The change in momentum of an object is equal to impulse delivered. So,
![F\times t=mv\\\\F=\dfrac{mv}{t}](https://tex.z-dn.net/?f=F%5Ctimes%20t%3Dmv%5C%5C%5C%5CF%3D%5Cdfrac%7Bmv%7D%7Bt%7D)
For 8 shot burst, average recoil force on the gun is :
![F=\dfrac{8mv}{t}\\\\F=\dfrac{7.5}{1000}\cdot\dfrac{300}{0.4}\cdot8\\\\F=45\ N](https://tex.z-dn.net/?f=F%3D%5Cdfrac%7B8mv%7D%7Bt%7D%5C%5C%5C%5CF%3D%5Cdfrac%7B7.5%7D%7B1000%7D%5Ccdot%5Cdfrac%7B300%7D%7B0.4%7D%5Ccdot8%5C%5C%5C%5CF%3D45%5C%20N)
So, the average recoil force on the gun during that 0.40 s burst is 45 N.
Answer:potential difference is more or less like voltage. Using ohms, V=IR
Where V is Voltage
I is Current =0.4A
R is Resistance=20ohms
V=0.4*20
V=8V
Hence the potential difference will be 8V.
ii) V=0.4*30
V=12V
Explanation:
The voltage of potential difference is directly proportional to the current and the resistance. So if one increase or decrease, it will have impact on the other.
From the calculations, when the resistance increase, the voltage will increase to appreciate the change.
Answer:
the second time there is a gas between you and the star,
Explanation:
When you observe the star for the first time you do not have a given between you and the star, therefore you observe the emission spectrum of the same that is formed by lines of different intensity and position that indicate the type and percentage of the atoms that make up the star.
When you observe the same phenomenon for the second time there is a gas between you and the star, this gas absorbs the wavelengths of the star that has the same energies and the atomisms and molecular gas, therefore these lines are not observed by seeing a series of dark bands,
The information obtained from the two spectra is the same, the type of atoms that make up the star