Answer is C. Because protons and neutrons are more massive then electrons so that means A and b and C are not right
Answer:
The magnitude of the electrostatic force is 120.85 N
Explanation:
We can use Coulomb's law to find the electrostatic force between the down quarks.
In scalar form, Coulomb's law states that for charges 
and 
separated by a distance d, the magnitude of the electrostatic force F between them is:
where 
is Coulomb's constant.
Taking the values:
and knowing the value of the Coulomb's constant:
Taking all this in consideration:
<span>From the point of view of the astronaut, he travels between planets with a speed of 0.6c. His distance between the planets is less than the other bodies around him and so by applying Lorentz factor, we have 2*</span>√1-0.6² = 1.6 light hours. On the other hand, from the point of view of the other bodies, time for them is slower. For the bodies, they have to wait for about 1/0.6 = 1.67 light hours while for him it is 1/(0.8) = 1.25 light hours. The remaining distance for the astronaut would be 1.67 - 1.25 = 0.42 light hours. And then, light travels in all frames and so the astronaut will see that the flash from the second planet after 0.42 light hours and from the 1.25 light hours is, 1.25 - 0.42 = 0.83 light hours or 49.8 minutes.
Answer:
Oil : about 50years
Gas: about 52years
Coal: about 114years
Explanation:
Oil
Globally, we currently consume the equivalent of over 11 billion tonnes of oil from fossil fuels every year. Crude oil reserves are vanishing at a rate of more than 4 billion tonnes a year, so if we carry on as we are, our known oil deposits could run out in just about 50 years.
Gas
If we increase gas production to fill the energy gap left by oil, our known gas reserves only give us just 52 years left.
Coal
Although it’s often claimed that we have enough coal to last hundreds of years, this doesn’t take into account the need for increased production if we run out of oil and gas.
If we step up production to make up for depleted oil and gas reserves, our known coal deposits could be gone in 114 years.
If you look at the units of density, g/cm^3 you will see it's grams divided by volume (cm^3).
218.9 g / (0.5*1.55*25 cm^3) = 11.3 g/cm^3
