Reading a scale as a function of time (need formula)

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The discussion focuses on deriving a formula for the scale reading as a function of time when water is added to a pan at a constant rate. The initial formula proposed includes gravitational acceleration and the height of the water, but it was noted that the height variable is unnecessary. Participants highlighted that the formula must accurately reflect the scale reading at specific times, particularly at t=sqrt(2h/g). There is confusion regarding the correct representation of the scale reading at that critical time point. The conversation emphasizes the need for a simplified formula that excludes height while accurately calculating the scale reading over time.
pinkybear
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Homework Statement


A scale is adjusted so that when a large, shallow pan is placed on it, it reads zero. A water faucet at height h = 3.1 m above is turned on at t=0 and water falls into the pan at a rate R = 0.16 kg/s.

Determine a formula for the scale reading as a function of time t for t > sqrt(2h/g).
Express in terms using some or all of the variables: h,R,t

AND

Replace the pan with a tall narrow cylindrical container with Area of 11 cm^2 and find reading for t=9.2 s

The Attempt at a Solution


I got this
g*R*(t-sqrt(2h/g))+R*sqrt(2gh)
but it says i don't need the h variable, I'm stuck..

...the function of time is the time it takes for the water to fall 3.1 meters plus the rate times time?
 
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pinkybear said:

The Attempt at a Solution


I got this
g*R*(t-sqrt(2h/g))+R*sqrt(2gh)
but it says i don't need the h variable, I'm stuck..

...the function of time is the time it takes for the water to fall 3.1 meters plus the rate times time?
One problem with your formula is that it gives the incorrect reading at t=sqrt(2h/g). What should the reading be at that time, and what does your formula give for the reading?
 

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