10. A team of people who traveled to the North Pole by dogsled lived on butter because they needed to consume 6000 dietician's Calories each day. Because the ice there is lumpy and irregular, they had to help the dogs by pushing and lifting the load. Assume they had a 16-hour working day and that each person could lift a 500-N load. How many times would a person have to lift this weight 1.00 m upwards in a constant gravitational field, where g = 9.80 m/s², to do the work equivalent to 6000 Calories? (A) 50.2 (B) 492 (C) 5130 (D) 50200 (E) 492000

7. Angie says that an object is in equilibrium if the net torques about the center of mass is zero. Robbie says an object is in equilibrium if the sum of external forces is zero. Which one, if either, is correct? (A) Both are correct: an object is in equilibrium if either condition holds. (B) Neither is correct: both conditions must hold simultaneously. (C) Neither is correct: the net external force and the net external torque about any axis must be zero. (D) Neither is correct: an object is in equilibrium only if its velocity is zero in all coordinate systems. (E) Both are correct: if the sum of the external forces is zero, the net torque about any axis is automatically zero, and vice versa.

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