5 Written Questions
5 Matching Questions
- Rotational inertia (often called moment of inertia)
- Stick about CG:
- potential energy
- Conservation of energy for machines
- a The product of force and lever-arm distance, which tends to produce rotation.
Torque = lever arm × force
- b Energy of position, usually related to the relative position of 2 things, such as a stone and the earth, or an electron and a nucleus.
- c The work output of any machine cannot exceed the work input.
- d I = 1/12 mL²
- e The property of an object that measures its resistance to any change in its state of rotation: if at rest, the body tends to remain at rest; if rotating, it tends to remain rotating and will continue to do so unless acted upon by a external net torque.
5 Multiple Choice Questions
- ¹Physics types usually describe rotational speed, ω, in terms of the number of "radians" turned in a unit of time. There are a little more than 6 radians in a full rotation (2π radians, to be exact). When a direction is assigned to rotational speed, we call it rotational velocity). Rotational velocity is a vector whose magnitude is the rotational speed. By convention, the rotational velocity vector lies along the axis of rotation.
- The average position of weight or the single point associated with an object where the force of gravity can be considered to act.
- a = v^2/r = 4rπ^2/T
where v = velocity, r = radius, T = period
- 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.
- Device for increasing (or decreasing) a force or simply changing the direction of a force
5 True/False Questions
center of mass → Point at the center of an objects mass distribution, where all its mass can be considered to be concentrated. For everday conditions, it is the same as the center of gravity.
conservation of energy → In the absence of a net external force, the momentum of an object or system of objects is unchanged.
centripetal force → Apparent outward force on a rotating or revolving body.
torque → Product of force or lever arm distance, which tends to produce rotational accelertion.
axis (pl. axes) → I = ½ mr²