- #1
Eitan Levy
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Homework Statement
A closed funnel is 10 meters above a weighing scale. At t=0 we open the funnel. and 15kg of sand are coming out of it every second. The velocity of the sand when it comes out is 13m/s, directed downwards (towards the scale). At a certain moment the scale displays a value of 700N. What is the mass of sand on the scale at this moment?
Assume the sand loses its velocity the moment it hits the scale.
Homework Equations
F=dP/dt
Kinematics
The Attempt at a Solution
I am having trouble understanding why the mass won't simply be 700/g. If the sand is on the weight it has no velocity, no acceleration - it has a constant velocity of 0, doesn't it?
Any help would be appreciated.