Question

when is the acceleration due to gravity positive or negative ?

Answer 1

@Loser66

Answer 2

i dont understand when gravity is possitive or negative in a problem

Answer 3

the way i see it is this way

Answer 4

when you like going ,flaying in the space so the gravity is negativ bc. this force action in direction of central of the Earth

Answer 5

but doent work

Answer 6

Gravity (on a planet) is always towards the centre of the earth.
So if the positive displacement direction is towards the centre of the earth, g >0.
If, as we normally do, y is upwards, then any acceleration is negative.

Answer 7

yes mathmate exactly what i trayd saying above

Answer 8

*....acceleration due to gravity is negative.

Answer 9

@jhonyy9
Sorry I was busy typing and did not notice what you were typing! lol

Answer 10

np

Answer 11

so basically when an object is thrown upward its gravity due to acceleration is negative, downward is possitive

Answer 12

did i get it right?

Answer 13

If y is positive upwards, then \(acceleration\) due to gravity is always negative.
However, if the object is moving upwards, the velocity decreases with time because of the negative acceleration.
If the object is moving downwards, the \(magnitude\) of the velocity increases, but velocity still decreases (because of the negative acceleration), since the velocity downwards is negative.

Example:
object upwards:
velocity with time: 40 f/s, 8 f/s, -24 f/s, -56 f/s, ....

Object moving downwards,
velocity with time: -10 f/s, -42 f/s, -74 f/s, ....

In both cases, acceleration is negative.

Answer 14

alright thanks guys