1.47x10^5 Joules
The gravitational potential energy will be the mass of the object, multiplied by the height upon which it can drop, multiplied by the local gravitational acceleration. And since it started at the top of a 60.0 meter hill, halfway will be at 30.0 meters. So
500 kg * 30.0 m * 9.8 m/s^2 = 147000 kg*m^2/s^ = 147000 Joules.
Using scientific notation and 3 significant figures gives 1.47x10^5 Joules.
Answer:

Explanation:
Given:
- mass of rocket,

- time of observation,

- mass lost by the rocket by expulsion of air,

- velocity of air,

<u>Now the momentum of air will be equal to the momentum of rocket in the opposite direction: </u>(Using the theory of elastic collision)



The term pressure refers to the force per area created by the weight
of anything whose weight is distributed over an area, such as the
Earth's atmosphere, a lake, a gas inside a sealed jar, or a pointy
high heel.
I think it’s A protons .. hope this helps