- #1
Jimbo57
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Homework Statement
A 100 lb bag of sand is lifted for 2 seconds at the rate of 4 feet per second . find the work done in lifting the bag if the sand leaks out at the rate of 1.5 lbs per second.
Homework Equations
The Attempt at a Solution
Here's my attempt at it:
work = force x distance
force = 100-1.5t
distance = 4t
work = 400t-6t2
Now I integrate for t=2 and t=0
∫(400t-6t2)dt
=200t2-2t3 for t=2 and t=0
=800-16=784ft-lb
Any mistakes?