5 Written questions
5 Matching questions
- Solid sphere about CG:
- Formula for Torque
- Tangential speed~
- Re call the equilibrium rule in Chapter 2--that the sum of the forces acting on a body or any system must equal zero for mechanical equilibrium. That is, ∑F = 0. We now see an additional condition. The *net torque* on a body or on a system must also be zero for mechanical equilibrium...
- rotational inertia
- a ~radial distance × rotational speed.
In symbol form, v ~ rω
- b Torque = r x F
where r = the displacement vector, F = the force vector
- c Reluctance or apparent resistance of an object to change its state of rotation, determined by the distribution of the mass of the object and the location of the axis of rotation or revolution.
- d ...(∑T = 0, where T stands for torque). Anything in mechanical equilibrium doesn't accelerate--neither linearly nor rotationally.
- e I = 2/5 mr²
5 Multiple choice questions
- Newton's First Law states that a body in motion stays in motion at a constant speed and in a straight line unless acted upon by a net force; therefore, a force must be pulling inward on an object moving in a circular path in order to prevent it from moving in a straight path.
- I = ½ mr²
- This force is not an actual force; it is a fictitious force that seems to pull outwards on an object on a circular path. This effect is due to inertia, or the tendency for a moving object to follow a straight path.
- the amount of time it takes to complete one cycle (1 revolution)
- Motion of an object turning around an axis that lies outside the object.
5 True/False questions
Pendulum → an object hanging from a fixed point which, when pulled back and released, is free to swing back down by gravity and inertia
Conservation of angular momentum → When no external torque acts on an object or a system of objects, no change of angular momentum can occur. Hence, the angular momentum before an event involving only internal torques or no torques is equal to the angular momentum after the event.
Revolve → Device for increasing (or decreasing) a force or simply changing the direction of a force
tangential speed → Linear speed along a curved path.
center of mass → Point at the center of an objects weight distribution, where the force of gravity can be considered to act.