Answer:
28
Explanation:
Velocity ratio= Radius of wheel/radius of axle
Radius of wheel= 4.125 inches
Radius of axle= 0.125 inches
Velocity ratio = 4.125/0.125 = 33
Then;
Efficiency = mechanical advantage/velocity ratio × 100
Since the efficiency of the system = 85%
85 = mechanical advantage/33 × 100
Mechanical advantage = 85 × 33/100 = 28
Answer: option C. 2 and 3.
Explanation:
1) Isotopes are atoms of a same element with different number of neutrons. That means that the isotopes of a same element have the same number of protons, since the number of protons is what identify an element.
2) For example, all the atoms of oxygen have 8 protons. But isotope oxygen-16 has 8 neutrons, while oxygen-18 has 10 neutrons.
3) In the figure there are 3 different atoms:
i) atom # 1 has 5 protons and 7 neutrons
ii) atom # 2 has 6 protons and 7 neutrons
iii) atom # 3 has 6 protons and 8 neutrons.
4) Hence the atoms with the same number of protons and different number of neutrons are the #2 and the # 3. So, they are the isotopes of the same element.
Sodium-22 remain : 1.13 g
<h3>Further explanation
</h3>
The atomic nucleus can experience decay into 2 particles or more due to the instability of its atomic nucleus.
Usually, radioactive elements have an unstable atomic nucleus.
General formulas used in decay:

T = duration of decay
t 1/2 = half-life
N₀ = the number of initial radioactive atoms
Nt = the number of radioactive atoms left after decaying during T time
half-life = t 1/2=2.6 years
T=15.6 years
No=72.5 g

Answer: 1.Stars are born in clouds of gas and dust called nebulas.
2.The gas and dust are pulled together by gravity.
3.Heat and pressure cause nuclear fusion, which signals the birth of a star.
Explanation:
Answer:
It will mess up the orbit around the sun
Explanation: