As we know that in transformers we have

here we know that



now from above equation we will have



Because of the hint we can conclude what equation we need to solve this problem. We have power and duration that means that we need to express energy:
1 joule = 1watt * 1 second
or
E (energy) = P (power) * t (time duration)
E = 350 * 30 = 10500 joules.
The answer is (a).
Golf balls have a higher density than water hence sink to the bottom.
Answer:
D. A zinc Zn contains 30 protons inside the nucleus and 30 electron outside the nucleus