Not only is it common for companies to assign you more work than you can do in 40 hours while asking you to work no more than 40 hours, but it's also quite common for them to make you feel inferior if you don't accomplish the assigned herculean labors in 40 hours or less.
I had a boss who would constantly tell us about some wizard team mates of his at another company who could perform miracles and knew everything. I'm sure he thought that he was inspiring us, but it actually made at least me feel like a complete bozo.
No, I can't perform miracles. I don't know everything. I have better things to do with my time than devote my life and my blood to the corporation.