Two students each carry a box up to the third floor of a building. The total mass of each student and the box she is carrying is the same. Roberta makes the trip in 45 s while
Mary takes 30 s. Which of the following statements best describes this task?

A. Roberta has a greater power output than Mary
B. Mary does more total work than Roberta
C. Roberta does more
Total work than Mary
D. Mary has a greater power output than Roberta

Special care would be an answer

The figure is missing but we can answer anyway.the correct answer is "releasing the string". in fact, when the person is holding the bow and the arrow, the kinetic energy of the arrow is still zero (because the arrow is not moving). the moment the arrow is released, it acquires a velocity v, so its kinetic energy will become different from zero: where m is the mass of the arrow and v its velocity.  all the other options, instead, do not increase the kinetic energy of the system: -  pulling farther back on the string : this will just increase the elastic potential energy of the system-  holding the arrow higher: this will increase the gravitational potential energy of the system (which is given by u=mgh, where h is the height above the ground)-  decreasing the mass of the arrow: this will decrease the gravitational potential energy of the system (which is given by u=mgh, where m is the mass)

If the woman is just hanging off the bar then i think each arm will support 350n  and if she accelerates 1400n