Rock Grinding
Posted in Arts and Crafts on 04/10/2010 04:25 pm by adminRock Grinding
When the rock hits the ground, how much force does the ground exert on the rock during the collision?
Suppose you drop 20 kg rock from a height of 5 m above a recently watered lawn. When the rock hits the ground, how much force does the ground exert on the rock during the collision?
1. 400 N
2. 600 N
3. More information is needed.
3. More information is needed.
You need the time to stop to calculate the force. You can calculate the momentum change from
p = sqrt(2*m*K) where K = U at the top = m*g*h
So p = sqrt(2*20*20*9.8*5) = 198kg-m/s
so the force would be 198/t
“Circumfusion” – gullet-grinding synth rock by Parallax!
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