- #1
webren
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I have a question about this problem:
"A block is given an initial velocity of 5.00 m/s up a frictionless 20.0(degrees) incline. How far up the incline does the block slide before coming to a rest?"
The book gives a clue stating that mgx = -mgsin20.0 and mgy=-mgcos20.
My question is why is mgx negative mgsin20?
When I work it out:
Sum of x force = mgsin20 = ma,
therefore: a = gsin20
Do they make it negative because the force of gravity in the x direction is going in a negative direction while the velocity is going in a positive direction?
"A block is given an initial velocity of 5.00 m/s up a frictionless 20.0(degrees) incline. How far up the incline does the block slide before coming to a rest?"
The book gives a clue stating that mgx = -mgsin20.0 and mgy=-mgcos20.
My question is why is mgx negative mgsin20?
When I work it out:
Sum of x force = mgsin20 = ma,
therefore: a = gsin20
Do they make it negative because the force of gravity in the x direction is going in a negative direction while the velocity is going in a positive direction?