(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

So the concept is, you've got a very large slab of stone. For arguments sake, lets say it's about 8 feet high, 4 feet accross, and 2 feet thick. How much force would it take to push the slab over, pushing at the top for maximum torque. If granite weighs about 165 lbs/cubic ft, would a human be able to push this object over? How about if it was only 1 foot thick, or 6" thick?

2. Relevant equations

3. The attempt at a solution

I tried some things using torque but I think I was way off. I took one of the bottom edges as the point of rotation and using the thickness of the slab as the radius, and multiplying by the force of gravity, I got a torque, namely 9.8m/s * 4800 kg * .6 m, and used that resulting torque as the required torque to oppose gravity and rotate the object about that edge. That resulted in a very large # of 28224 N*m. This torque I then set equal to the unknown force time the height of slab (the new rotational edge) getting F = 28224 N*m / 2.4 m = 11760 N. That seems huge. That means even if the object were 100 feet tall and still weighed the same, it would take 940 N of force to tip it. Or if the base was 6" instead of 2', it would still take 2987 N. That still seems like a big number, as in my mind a 100 ft tall object with a 2 ft base would be highly unstable. Am I taking a completely wrong approach to sovling this or are those #'s right?

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# Homework Help: Not homework, but question about pushing over a heavy slab at rest

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