BB SA Overtime Pay Confusion?

Hey monkeys, just curious about something that I noticed in a contract and was hoping that some of you could share your thoughts and experiences...

Recently accepted a SA position at a top BB. It seems as the pay is constantly fluctuating based on the hours you work. Since you are not a salaried employee, this makes logical sense, and if you're paid at the street entry level rate of $85k as all BBs do, assuming a 40 hr work week, your hourly rate would be 85000/52= 1632 and then /40 to get approximately $41 per hour.

The contract says that this will fluctuate based on the hours you work per week, giving the following formula: When you work over 40 hours a week, your overtime pay will be calculated by dividing the weekly rate by the total number of hours you worked in the week. Then, you multiply that rate of pay for the week by .5 overtime.

The following example illustrates it: If your salary is equivalent to $52,000.00 per year and you worked 50 hours in a given workweek, your regular hourly rate of pay for that workweek would be $20.00 per hour ($1,000.00 weekly rate / 50 hours of work). Your overtime compensation for that workweek would be $100.00 ($20.00 per hour * .5 overtime premium * 10 hours of overtime). Under this calculation method, your weekly overtime compensation will vary.

Is this the norm? I was a bit surprised as I've heard different stories from friends over the years according to how this works, and in all honesty, I'm surprised. I don't know if it's because I was given wrong information from others or whether or not I'm misunderstanding how this works, or whether this is just how this is. If you're considering this $41/hr rate your overtime should be close to $62/hr. With this, it looks like they are trying to dissuade people from pushing overtime, something that will certainly be impossible given the work, and will effectively drop your hourly pay lower to combat the spread. I did the math to see the 60-80-100 hour week numbers and it comes out being numbers that I never would have expected. Just worried about being dicked if it's supposed to be different, or whether or not this is just how it operates.

Just wanted to find out if this is how it's supposed to be, or if I was misunderstanding something. Thanks all..