Physics when is gravity positive

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Wolphram jonny Wolphram jonny 1. Recall from an earlier lesson that acceleration is the rate at which an object changes its velocity. It is the ratio of velocity change to time between any two points in an object's path. To accelerate at 9. If the velocity and time for a free-falling object being dropped from a position of rest were tabulated, then one would note the following pattern.

Observe that the velocity-time data above reveal that the object's velocity is changing by 9. That is, the free-falling object has an acceleration of approximately 9.

Another way to represent this acceleration of 9. Consider I scream: "look out, a car is approaching!!! It depends because the car could go towards you or away from you. You see that direction is necessary and qualifies an important characteristic of some quantities such as velocity, force or acceleration without it it would be difficult to qualify completely these quantities and be able to use them. When we do the calculations and decide for a positive direction we drop the arrow and use plus or minus in front of the values to indicate their directions.

What I suggest is to revise VECTORS first and then every time you have a problem involving forces or any other vector quantity first of all define a positive direction and refer to this for all your vector quantities. So if one of your vectors, say acceleration, is pointing in the opposite direction to the positive one we will use a minus sign in front of its value to express this direction in all the formulae we use you can appreciate that we need a way to discriminate between the two possibilities: acceleration in the same positive direction from acceleration in the opposite direction As you can see from the diagram the force a vector produced by a NEGATIVE opposite to the positive direction acceleration will retain the negative sign indicating that it will also be directed in the opposite direction from the positive one.

Very good answer above. I just wanted to throw out a quick tip for determining whether you should use g or -g.