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M1 SUVAT help

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Oh alright, I wasn't sure whether to use negative or positive 9.8

Well it depends on the direction you take, if you take upwards as the positive direction then it is -9.8, if you use downwards then it is 9.8. If you think about it gravity is acceleration in a downwards direction, so it makes for it to be positive in that direction and negative when going upwards :smile:

Reply 21

Asciant

Original post by TLK

It can since its a vector quantity. It can have a negative value depending on which direction you make positive.

Original post by TenOfThem

It is 9.8 in a downwards direction

If the OP chose to take up as the positive direction then a would be -9.8

I know, my answer was referring to the example I quoted from OP :smile:

Reply 22

TenOfThem

Original post by Diaz07

Ahh okay, so if I pick down as positive both gravity and displacement will be positive in the downwards direction, I get it now thanks! But could you explain why you used positive 9.8 as the object is going up and then down, not just down if you get me?

gravity is always acting downwards no matter how the item is travelling

velocity will change depending on the direction of travel but not acceleration due to gravity

Reply 23

Diaz07

Original post by TenOfThem

gravity is always acting downwards no matter how the item is travelling

velocity will change depending on the direction of travel but not acceleration due to gravity