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I want to check myself on some basic things: Assume I am holding a heavy bowling ball straight out in front of me. And assume that when I walk I am able to carry the ball in such a way that it strictly moves in a straight line parallel to the ground (so at a fixed height). My question is: are the following three statements true?

  1. If I walk at the constant velocity $\vec{v}=1\hat{i}$ and there is no drag then no work is being done on the bowling ball
  2. If I walk at the constant velocity $\vec{v}=1\hat{i}$ and there is drag then both I and the air are doing work on the ball: $W_{air on ball}=-W_{meonball}$
  3. If I accelerate while I walk such that my velocity is $\vec{v}=a_{walk}t\hat{i}$ and there is no drag then, for a walk of length $\Delta x$, $W_{meonball}=m_{ball}a_{walk}\Delta x$
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  • $\begingroup$ I removed a couple of comments; please keep in mind that comments are to be used for suggesting improvements and requesting clarification on their parent post, not for answering the question. $\endgroup$ – David Z Nov 28 '18 at 5:07
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$W = F\Delta d$

where $\Delta d$ is in the direction of the force.

  • Question 1: $\Delta d$ is zero, so no work. Your assertion is true.
  • Question 2: $F$ is the drag, $\Delta d$ is the distance walked. Your assertion is true.
  • Question 3: Since $F = ma$. Your assertion is true.
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