Work and Kinetic Energy Problem for Pump

AI Thread Summary
The discussion revolves around calculating the work done by a pump lifting 800 kg of water from a 14 m deep well and giving it kinetic energy. The initial calculations suggest that the work done in lifting the water is 5600 J, while the kinetic energy imparted is 12000 J. However, a more comprehensive approach indicates that the total work done should include both gravitational potential energy and kinetic energy, resulting in a total of 469872 J for lifting and 360000 J for kinetic energy. Participants emphasize the importance of using the correct equations and considering all energy components in the calculations. The thread highlights the need for accuracy in homework solutions and adherence to forum guidelines.
marckc22
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Homework Statement


A pump is required to lift 800 kg. ( about 200 gallons) of water per minute from a well that is 14.0 m deep and eject it with a speed of 30 m/s
a.) how much work is done per minute in lifting the water?
b.) how much in giving it kinetic energy?

Homework Equations


W = Fd
F = ma
a = V/t
KE = 0.5(m)v^2


The Attempt at a Solution


a = v/t = (30 m/s)/(60s) = 0.5 m/s^2

F = ma = 800(0.5) = 400 N

W = (400 N)(14 m) = 5600 J

My answer for letter a. W = 5600 J

KE = 0.5(m)v^2 = 0.5(800)(30) = 12000 J

My answer for letter b. KE = 12000 J

Am i right? please let me know if there are any mistakes. Thank you...
 
Physics news on Phys.org
a) W = mgh+ \frac{1}{2} mv^2 = 800kg*14m*9.81ms^{-2}+\frac{1}{2}*800kg*(30m/s)^2 = 469872J
b) \frac{1}{2}mv^2 = \frac{1}{2}*800kg*(30m/s)^2 = 360000J
 

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