Answer:
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Explanation:
From the exercise we know two information. The real speed and the experimental measured by the speedometer
Since the speedometer is only accurate to within 0.1km/h the experimental speed is
Knowing that we can calculate Kinetic energy for the real and experimental speed
Now, the potential error in her calculated kinetic energy is:
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Answer:
-1.43 m/s relative to the shore
Explanation:
Total momentum must be conserved before and after the run. Since they were both stationary before, their total speed, and momentum, is 0, so is the total momentum after the run off:
where are the mass of the swimmer and raft, respectively.
are the velocities of the swimmer and the raft after the run, respectively. We can solve for
So the recoil velocity that the raft would have is -1.43 m/s after the swimmer runs off, relative to the shore