Physics CH 10-11 Vocabulary
Terms in this set (26)
the axis is the straight line around which rotation takes place.
an axis that is located within the body of the object
an axis that is located outside the body of the object
rotation is a motion of an object turning about an internal axis.
revolution is a motion of an object turning about an external axis.
linear speed is the distance traveled per unit of time.
tangential speed is the speed of something moving along a circular path.
tangential speed is directly proportional to radial distance * rotational speed. v ~ r w
rotational speed AKA angular speed is the number of rotations per unit of time.
tangential speed concept
tangential speed depends on rotational speed and the distance from the axis of rotation.
centripetal force is the force directed toward a fixed center that causes an object to follow a circular path.
centripetal force concepts
the centripetal force on an object depends on the object's tangential speed, its mass, and the radius of its circular path.
centripetal force formula
centripetal force = (mass * speed) / radius of curvature; Fc = mv2/r
centrifugal force is a force that is "center fleeing" is one that moves away from the center.
centrifugal force concept
The centrifugal force effect is attributed not to any real force but to inertia - the tendency of the moving body to follow a straight line path. Centrifugal force is an effect of rotation. It is not part of an interaction and therefore it cannot be a true force.
torque is produced by a turning force and tends to produce rotational acceleration. Torque causes rotation.
to make an objec turn or rotate, apply a torque.
a lever arm is when the force is perpendicular, the distance from the turning axis to the point of contact is called the lever arm.
When balanced torques act on an object, there is no change in rotation.
center of mass
center of mass is a point in an object as if all the mass were concentrated at this point.
location of the center of mass
The center of mass of an object is the point located at the object's average position of mass.
center of gravity
the center of mass is often called the center of gravity which is the average position of all the particles of weight that make up an object. For everyday objects, the center of gravity is the same as the center of mass. The center of gravity of a person is not located in a fixed place, but depends on body orientation.
rules for toppling
If the center of gravity of an object is above the area of support, the object will remain upright.
unstable equilibrium is where an object is balanced so that any displacement lowers it center of mass.
stable equilibrium is where an object is balanced so that any displacement raises its center of mass.
neutral equilibrium is where an object is balanced so that any small movement neither raises nor lowers it center of gravity.