Mechanics II Flashcards
center of mass
the point at which we consider all the mass of the object to be concentrated, at this point, the object behaves as if the object was a single particle
uniform circular motion
an object moving in a circular path at a constant speed
centripetal force
the net force directed toward the centre of the circle, makes an object turn to follow a circular path (changes direction)
tangential acceleration
changes speed of movement
torque
the measure of a force’s effectiveness at making an object spin or rotate
pivot point/fulcrum
the “centre” of turning, the point that does not move while the remainder of the object is rotating, acts like the centre of a circle
is torque a force?
no, it is a property of force
radius vector, r
the vector from the centre of rotation (pivot point) to the point of application of the force
what are the signs for torque?
counter-clockwise rotation is positive, clockwise rotation is negative
what is the torque if the force acts at the pivot or along a line through the pivot?
the torque would be zero
equilibrium
zero acceleration
translational equilibrium
net force is zero, translational acceleration is zero
rotational equilibrium
net torque is zero, rotational acceleration is zero
static equilibrium
net force is zero and net torque is zero
rotational inertia (moment of inertia), I
indicates how resistant an object is to rotational acceleration
