- #1
rambo5330
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- 0
Homework Statement
I was asked a very simple question today about finding the tension in a cable as a 1200kg elevator is accelerating downward at -1.05 m/s^2 . now I could answer the question easily
ma = T - mg
solve for T but what I couldn't answer was just the basic question when the peer asked mee why isn't gravity negative in this case. and that got me thinking why isn't gravity negative in the applications of Newtons laws?
If I have a 60 kg object sitting stationary on the ground it will have a normal force of N = mg obviously the object isn't accelerating in any direction but why are able to consider the acelleration of gravity as being positive in these scenarios? It's probably been explained several times on here but after searching I have found nothing that explains it in any detail.