In which one of the following situations are you doing (positive) work on a sack of flour?
A. When you carry it horizontally at constant velocity.
B. When you lower it downward at constant velocity from a high shelf to the floor.
C. When you drag it horizontally across the floor at constant velocity.
D. When you hold it motionless above your head.
Answer:C
In which one of the following situations are you doing (positive) work on a sack of flour?
A. When you carry it horizontally at constant velocity. B. When you lower it downward at constant velocity from a high shelf to the floor. C. When you drag it horizontally across the floor at constant velocity. D. When you hold it motionless above your head.