- #1
allok
- 16
- 0
hi
I'm stuck so I'd like to ask a couple of questions about circular motion.
1*I know that for certain radius R and certain centripetal acceleration vector ( centr. acc. vector ), magnitude of velocity has to be just right for object ( either point mass or rigid body ) to go in circles. Because then acc. vector is perpendicular to velocity vector and thus it only changes its direction, but not its magnitude. But why does magnitude of velocity have to be just right for acc. vector to be perpendicular to velocity?
Why if object's velocity is too slow are centr. force and thus centr. acc not perpendicular to velocity?
Does acc.vector ( at the moment magnitude of velocity gets too slow for object to circle ) pull object in such position that cent. force is no longer perpendicular to object, and because of that object goes in some other, non circular path?
2*In first question I stated that for object to go in circles ( at known R and centr. acc. vector ), it must have certain speed. But that obviously is not true when acc. vector also has tangential component aka angular acc.
So how does object manage to go in circles even though the magnitude of its velocity is either increasing or decreasing?
Is it because component ( of acc vector ) perpendicular to velocity also keeps changing ? If magnitude of velocity keeps getting bigger, then in order for an object to keep going in circles, acc vector directed towards the center of circle must also keep getting bigger (i.e. centripetal force must keep getting bigger as long as magnitude of velocity is getting bigger ). And reason for that is because greater the magnitude of velocity vector, the greater must its change in direction be?
thank you
I'm stuck so I'd like to ask a couple of questions about circular motion.
1*I know that for certain radius R and certain centripetal acceleration vector ( centr. acc. vector ), magnitude of velocity has to be just right for object ( either point mass or rigid body ) to go in circles. Because then acc. vector is perpendicular to velocity vector and thus it only changes its direction, but not its magnitude. But why does magnitude of velocity have to be just right for acc. vector to be perpendicular to velocity?
Why if object's velocity is too slow are centr. force and thus centr. acc not perpendicular to velocity?
Does acc.vector ( at the moment magnitude of velocity gets too slow for object to circle ) pull object in such position that cent. force is no longer perpendicular to object, and because of that object goes in some other, non circular path?
2*In first question I stated that for object to go in circles ( at known R and centr. acc. vector ), it must have certain speed. But that obviously is not true when acc. vector also has tangential component aka angular acc.
So how does object manage to go in circles even though the magnitude of its velocity is either increasing or decreasing?
Is it because component ( of acc vector ) perpendicular to velocity also keeps changing ? If magnitude of velocity keeps getting bigger, then in order for an object to keep going in circles, acc vector directed towards the center of circle must also keep getting bigger (i.e. centripetal force must keep getting bigger as long as magnitude of velocity is getting bigger ). And reason for that is because greater the magnitude of velocity vector, the greater must its change in direction be?
thank you