https://vsbattles.fandom.com/wiki/Calculations#Meteors_and_Kinetic_Energy
The equation used: Ek=0.5*M*V^2
Terms: Ek=Kinetic Energy M=mass V=velocity=speed
If the meteor in question was determined to have come from outer space (or outside of our atmosphere) we will use the value of minimum impact velocity, which is the minimum value of speed an object needs to enter the earths atmosphere, that value is
11,000 m/s.
If the meteor in question was shown to be Ablated, but didn't come from space, we will use Ablation speeds, which are the minimum speed an object needs to move in order for it to be ablated by its own friction with the atmosphere, the values range from
2000-4000 m/s.
A reasonable high end for meteors that come from outer space is
17,000 m/s, as it is the speed value of most of the meteors that have entered earths atmosphere.
It sounds like this meteor came from space. Since they're using metric, 300 trillion tons is probably metric tonnes. Presumably, our formula assumes kilograms for mass, & 1 metric tonne is 1,000 kg.
0.5 * 300,000,000,000,000 (three-hundred trillion) * 11,000^2 = 18,150,000,000,000,000,000,000 joules. So add another three zeroes to the end of that result.
18,150,000,000,000,000,000,000,000 joules or 1.815×10^25 . This is nearly the maximum yield of
6-A; 6-A's maximum yield is 1.855604x1025 which is just SLIGHTLY higher.
If we assume 17,000 m/s, the high end.... It only goes up to
4.335×10^25 joules . Barely even Multi-Continent Level (High 6-A.), but
High 6-A DOES peak at 1.24x1029 so not easy to break out of it anyway.