Did I Neglect the Skier in the Resistive Force Calculation?

AI Thread Summary
The calculation of the total resistive force for a boat with a skier is confirmed to be correct at 7000N, derived from the power output of 140kW and the speed of 20m/s. The masses of the boat and skier do not affect this specific calculation. The discussion clarifies that the total power output is indeed 140kW. The participant expresses initial doubt but receives reassurance about the accuracy of their calculations. Overall, the resistive force calculation stands validated despite concerns about neglecting the skier's mass.
Userxy
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Hi,
Imagine a boat with a skier behind it (connected with a rope).

Mass of boat=2000Kg
Mass of skier=80Kg
At 20m/s the boat engine has a power output of 140kW

Calculate the total resistive force.

Power=FxV
140000W=Fx20m/s
F=7000N

Is the answer right ? I doubt my answer, even if its really easy, because I totally neclected the skier.

Thanks!:wink:
 
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It's correct. The masses are irrelevant.
 
Paul Eccles said:
It's correct. The masses are irrelevant.
Okay, Thank you!
 
I think that 140kW is the total power. So is ok.
 

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