Scorch
06-03-2007 22:59:03
Anyone know a good forum post or website for equasions and related math for newton physics?
I havn't figured out how damping works yet, but here is my current understanding of force & acceleration equasions: ( for an object sliding/rolling on the level ground )
acceleration = ( ( force / mass ) - (friction * mass ) ) * time;
So if I know what the mass and friction are, and I know what I want my acceleration to be over a given time period, I can calculate the nessisary force right?
For example, if object is 10 kilograms and has a 0.1 friction and I want to be going 10 meters per second in 1 second from now, I would use the equasion:
1: starting equasion
acceleration = ( ( force / mass ) - (friction * mass ) ) * time;
2: divide both sides by time
acceleration / time = ( force / mass ) - ( friction * mass )
3: multiply both sides by mass
mass * ( acceleration / time ) = mass * ( (force/mass) - ( friction * mass * mass ) )
4: distribute mass on the right side
mass * ( acceleration / time ) = force - ( friction * mass * mass )
5: add ( friction * mass * mass ) to both sides
( mass * ( acceleration / time ) ) + (friction * mass * mass ) = force
6: reverse the sides of the ='s for readability
force = ( mass * ( acceleration / time ) ) + (friction * mass * mass )
plugging in data from my example:
force = ( 10 * ( 10 / 1 ) ) + ( 0.1 * 10 * 10 );
evalutating the equasion
force = 100 + 10
force = 110 newtons
example 2: if I want to have 0 acceleration and just maintain my current speed I would:
force = ( 10 * ( 0 / 1 ) ) + ( 0.1 * 10 * 10 )
force = 0 + 10
force = 10
is this right? Can someone double check my work? How does dampining fit into these equasions? I'm trying to avoid torque equasions just because I don't know the math right now.
The reason I want to know this, is I want to "set" my velocity without calling setVelocity because using setVelocity doesn't do well on climbing steep walls. ( I still plan on using setVelocity to stop though )
I havn't figured out how damping works yet, but here is my current understanding of force & acceleration equasions: ( for an object sliding/rolling on the level ground )
acceleration = ( ( force / mass ) - (friction * mass ) ) * time;
So if I know what the mass and friction are, and I know what I want my acceleration to be over a given time period, I can calculate the nessisary force right?
For example, if object is 10 kilograms and has a 0.1 friction and I want to be going 10 meters per second in 1 second from now, I would use the equasion:
1: starting equasion
acceleration = ( ( force / mass ) - (friction * mass ) ) * time;
2: divide both sides by time
acceleration / time = ( force / mass ) - ( friction * mass )
3: multiply both sides by mass
mass * ( acceleration / time ) = mass * ( (force/mass) - ( friction * mass * mass ) )
4: distribute mass on the right side
mass * ( acceleration / time ) = force - ( friction * mass * mass )
5: add ( friction * mass * mass ) to both sides
( mass * ( acceleration / time ) ) + (friction * mass * mass ) = force
6: reverse the sides of the ='s for readability
force = ( mass * ( acceleration / time ) ) + (friction * mass * mass )
plugging in data from my example:
force = ( 10 * ( 10 / 1 ) ) + ( 0.1 * 10 * 10 );
evalutating the equasion
force = 100 + 10
force = 110 newtons
example 2: if I want to have 0 acceleration and just maintain my current speed I would:
force = ( 10 * ( 0 / 1 ) ) + ( 0.1 * 10 * 10 )
force = 0 + 10
force = 10
is this right? Can someone double check my work? How does dampining fit into these equasions? I'm trying to avoid torque equasions just because I don't know the math right now.
The reason I want to know this, is I want to "set" my velocity without calling setVelocity because using setVelocity doesn't do well on climbing steep walls. ( I still plan on using setVelocity to stop though )