In order to keep a leaking ship from sinking, it is necessary to pump 11.0 lb of water each second from below deck up a height of 2.50 m and over the side. What is the minimum horsepower motor that can be used to save the ship?

2 answers

Power requirement = mass flow rate (slug/s) * potential energy gain per mass (ft-lb/slug)
= (11.0/32.2 slug/s) * (32.2 ft/s^2)*(8.20 ft) = 90.2 ft-lb/s
Divide by 550 ft-lb/s per HP to get horsepower.
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