This is an interesting essay prompt because it gives you so many possibilities about which to write--though perhaps that is part of the problem. Once you settle on your theme, I am confident this will be easy for you to write.
The prompt, "imbalances in power lead to conflict," forces you to think of all the possible imbalances of power which exist everywhere around us. Once you decide which one you connect with the most, you will certainly be able to think of conflicts which arise because of that imbalance.
Consider these imbalances:
Gender - in the workplace, for example, men far outnumber women in positions of power (and therefore salaries) and can use that power to abuse women in terms of sex, time, unreasonable expectations, and more.
Rank - this one concerns the military, where plenty of evidence has been gathered (and many lawsuits presented) that those in authority take advantage of their superior rank to obtain what they want, including sexual things.
Position - this is much like the above, but it is found in the civilian world. This would include teachers and students, policemen and perpetrators, employers and employees, coaches and players, parents and children, and more; the person with the power has the ability to create all kinds of conflicts, including abuse, favoritism, and discrimination.
Money - those who have it can certainly use it as a weapon against those who do not.
Race/ethnicity - while I wish this one were not on the list, there are still places where a person's race or ethnicity puts him in a position to be in the control or power of someone of a different race or ethnicity. Fortunately it seems the worst of this is over, but a looking back on some of the terrible injustices perpetrated against African-Americans would certainly yield plenty of examples of conflicts.
One other category is hard to put a name to, but as a student I am certain you will recognize it. Bullies are in a position of power, for whatever reason; when they assume the power over their peers, this will create conflicts. The interesting issue with this one is the exploration of what gives a bully his or her power; writing about the conflicts which come from that will be much simpler to explain.
The best advice I can give you is this (from the eNotes link below):
Your topic must have value to you. Given the hours you’ll need to invest in the paper, your topic needs to be more than “interesting”; it has to be knowledge you want to pursue for your own personal benefit, not just a grade.... Choose a topic you care about and are invested in. You’ll write better and research deeper because of your personal investment.
The nature of the prompt is persuasive/argumentative, so I have included a helpful eNotes link which will help you as you get ready to write.