- #1
Xeneize
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Hey guys, first post here...
So, I'm having an issue comprehending this topic:
Let's say you have a box which weighs 3 N, and you place a 7 kg block on top of it. So, since the block is laying on a horizontal plane, the weight is mg, or 6*10=60 N. Total weight=60+3=63
Let's say you have an inclined box 45 degrees to the ground (held by a stick of negligible mass, or whatever... just pretend that it is inclined) that weighs 3 N and you place a 6 kg block on top of it, and the friction causes it to remain at rest. My teacher said that the weight here is mgsin45, because Normal=mgsin45 at this case. So, (6)(10)(2...)=120ish N. Total weight=120+3=123.
What I don't understand, is why isn't the weight in BOTH cases mg? Because, if you put both systems each in a separate balance, the weight will be 63 N for both, amirite? The masses certainly don't change, you have the SAME box and the SAME block, except they are at different angles.
Por favor clarify :D
So, I'm having an issue comprehending this topic:
Let's say you have a box which weighs 3 N, and you place a 7 kg block on top of it. So, since the block is laying on a horizontal plane, the weight is mg, or 6*10=60 N. Total weight=60+3=63
Let's say you have an inclined box 45 degrees to the ground (held by a stick of negligible mass, or whatever... just pretend that it is inclined) that weighs 3 N and you place a 6 kg block on top of it, and the friction causes it to remain at rest. My teacher said that the weight here is mgsin45, because Normal=mgsin45 at this case. So, (6)(10)(2...)=120ish N. Total weight=120+3=123.
What I don't understand, is why isn't the weight in BOTH cases mg? Because, if you put both systems each in a separate balance, the weight will be 63 N for both, amirite? The masses certainly don't change, you have the SAME box and the SAME block, except they are at different angles.
Por favor clarify :D