Circular motion: (Picture attached)
What is the maximum speed the vehicle can have at B and still remain on the track?
I understand everything besides the reason why mg is positive instead of negative. OR why
-mg=-(mv^2)/r

Question

Circular motion: (Picture attached)
What is the maximum speed the vehicle can have at B and still remain on the track?
I understand everything besides the reason why mg is positive instead of negative. OR why  
-mg=-(mv^2)/r

happykiddo · Answer

attachment

anonymous · Answer

Is it because Mg is on the other side of the equation? Mg and centripetal force must be opposing, so must have opposite signs. If they are on opposite sides of the equation, they will have the same sign.

anonymous · Answer

The maximum speed will be where mg = Fc, so, mg - Fc = 0

vincent-lyon.fr · Answer

No, weight and centripetal force must be equal, not opposite.
Since weight is down and centripetal acceleration is towards the centre of the circle, they both have the same direction, hence mg = mv²/r

happykiddo · Answer

Yeah I don't get their explanations, could you explain it in terms of a drawing. Please and thank you.

happykiddo · Answer

Here is the exact problem from my test review it has an answer.

happykiddo · Answer

Yes horizontal, Sorry I lost internet connection.