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  1. I don’t think you should try catch concrete no mater what it’s packed in. Anyway it’s cement still need to add water and sand,

    1. Cement is one ingredient in concrete. It’s like flour is to bread. To say that is a bag of cement because it doesn’t have water yet is incorrect. It is still concrete (cement, sand, gravel and other ingredients), minus the water.

    2. The bag looks too flexible to contain concrete–or cement/mortar/grout/your-favorite-aggregate. It’s more likely a bag of flour or rice.

      That said, it looks like it’s being dropped around 8 feet (~2.3m)–from its launch until its interception about a meter off the ground.

      X = 2.3 m = 1/2*a*t^2 and a = 9.8 m/s/s, so t = 0.685

      So the bag travels about 0.7 seconds before the intercept, which means it’s travelling at that point around 6.7 m/s. So a 60 pound bag of rice would have an apparent weight of ~100 pounds.

      Any NFL player would have no problem catching that. Sanjit, here, looks more like a soccer player.

    3. Joe, your physics is not correct. The force the person catching the bag would encounter would be dependent on how quickly he could decelerate the bag. The basic equation F=ma would apply. m would be the mass of the bag, and a would be the deceleration rate (assuming constant). The quicker he stops the bag’s motion, the higher the deceleration and force. I don’t think apparent weight is applicable here, but it’s been a few years since my physics class.

    4. eh Blacktab. yes that is the case. You can’t call a bag of cement, concrete. It’s a bag of cement. Just within your own example Flour and bread. You wouldn’t describe a bag of flour as bread now would you.

    5. Drengi.  I see you tried to correct your original post by editing it.  My first response is still valid based on your unedited post in which you stated that cement becomes concrete when water is added.  I do want to point out that by only adding water and sand to cement, you will end up with grout, not concrete.

    6. Sup, Dog. Are you serious? You’re checking my MATH in a troll-post meant for the weenie soccer-ball-kicking gamma-males that haunt this site? Well… At least you’re not overly fascinated with the distinction between cement & concrete…

      So, yeah: my posted analysis was quite shorthand. Assuming the intercept began at 1 m above the ground and had to complete before the object hit the ground, the catcher/victim would have to exert a force of AT LEAST ~600 N on the falling object (which is more equivalent to 2.3 times its ‘normal’ weight) to arrest its motion. I doubt this adjustment will mean much to the gammas who are balancing soccer balls on their heads: They’re still weak–in mind and in body. And I assert an NFL player could do it.

  2. Also goes for shingles. Had a job working construction a couple of summers at which some guys thought it would be funny to toss bundles of shingles up to me further and further out from the edge for me to snag up. Got pulled off once and twisted my ankle and wrist real bad. A couple of the older guys I worked with felt bad about the whole thing and ran the roofers off and got a new crew before I returned from healing thankfully. Woulda probably cracked the guy with a shovel otherwise…

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