Let's stick to the subject.
Obviously, the H guy has not tried this himself...
Make it easy. Drop a 5 pound brick on the scale, after weighing it statically.
That way you don't break stuff--or not badly...
For the fence-sitting lurkers
(since I've given up on Heiwa)
Importantly: Video tape the experiment, and
record the weight reading in each frame.
Plot the recordings with respect to time.
It predict that the period of time when the force registering is
greater than the weight of the brick will exactly match the time between initial impact and the brick coming to a stop.
It will be quick, so a high-speed camera would help.
A simpler method is to have a scale that will record the maximum force.
Then, a simple calculation will verify the F=ma equation.
t1 = initial contact time
t2 = time when brick velocity = 0
v1 = velocity at impact (= [
2gd]
0.5 where
d = distance dropped)
v2 = velocity at time stopped (=0, obviously)
a = (
v2 -
v1)/(
t2 -
t1)
m is the mass of the brick.
F will be equal (within experimental error) to the average reading on the scale over the time of impact (
t2 -
t1).
F will also be higher than mg.
I like this experiment. It once again proves me and Dave Rogers are correct (ref. to the Pizza Tower thread) when we stated that in order to bring a falling object to a stop (which requires change in velocity, defined as acceleration) requires a retarding force
greater than the weight of the falling object.