College Physics Exam (2025 Latest Version) Latest Questions with Updated Answers Grade A.

College Physics Exam (2025 Latest Version) Latest Questions with Updated Answers Grade A. angular position theta positive angular position counter-clockwise rotation negative angular position clockwise rotation arc length the distance that the particle has traveled along its circular path (s) radians used to describe a particle's angle theta angular displacement the angular displacement through which the particle moves each second omega angular velocity (change in theta/change in time) uniform circular motion constant omega angular speed the absolute value of the angular velocity, it is positive no matter the direction of rotation angular velocity-versus-time graph created by using the slope of the corresponding angular position-versus-time graph speed V = (omega)(r) extended object system of particles for which the size and shape do make a difference and cannot be ignored rigid body an extended object whose size and shape do not change as it moves rigid-body model a good approximation for many real objects of practical interest, such as wheels and axles translational motion object as a whole moves along a trajectory but does not rotate rotational motion motion of objects that rotate about a fixed point; every point has the same angular velocity combination motion an object rotates as it moves along a trajectory nonuniform circular motion changing angular velocity angular acceleration (alpha) change in omega/change in time; slope of the angular velocity-versus-time graph angular velocity slope of the position-versus-time graph tangential acceleration measures the rate at which the particle's speed around the circle increases force factors 1. magnitude of the force 2. distance from the pivot 3. angle at which the force is applied Torque measures the effectiveness of a force at causing an object to rotate about a pivot; the rotational equivalent of force; = (r)(F perpendicular) F perpendicular only component that causes rotation, determines Torque line of action line that is in the direction of the force, and passes through the point at which the force acts moment arm the perpendicular distance from the line of action center of gravity an object's weight acts at a single special point on an object pivot point the center of gravity will always rotate to be below this moment of inertia proportionality constant between angular acceleration and net torque; rotational equivalent of mass period (T) the time it takes for an object to turn one revolution rolling constraint the basic link between translation and rotation for objects that roll without slipping static equilibrium the net torque about every point must be zero stablility when an object is in its equilibrium position; a wider base of support and/or lower center of gravity improves this critical angle when the center of gravity is directly over the pivot point; point of balance, no net torque unstable gravitational torque causes rotation base of support track width restoring force a force that brings a system to an equilibrium position elastic systems that exhibit restoring forces spring force this is proportional to the displacement of the end of the spring spring constant k; depends on area, length, and stiffness of an object Hooke's Law relationship between the restoring force and the displacement of the end of a spring rigid materials experiences only small changes in dimension pliant materials materials that show large deformations with small forces Young's modulous a property of the material from which the rod is made tensile stress stress due to stretching; the largest stress that a material can sustain before breaking linear region if within this, a solid rod will return to its normal length and obey Hooke's Law elastic limit a stretch must be less than this for an object to return to its original length elastic region the elastic limit makes up the end of this collision a short-duration interaction between two objects impulsive force a large force exerted during a short interval of time impulse area under the force-versus-time curve impulsive force effects proportional to the area under the force-versus-time graph momentum product of the object's mass and velocity impulse momentum theorem an impulse delivered to an object causes the object's momentum to change if the duration of a collision ____, the force of the impact ____ increases, decreases total momentum the vector sum of the momenta of each individual particle included in the system impulse approximation ignoring small negligible forces during the brief time of the impulsive force conserved momentum there is no change in the total momentum of a system external forces forces from agents outside of the system when Fnet = 0 the total momentum of the system does not change isolated system no net external forces acting on a system; total momentum is constant Law of Conservation of Momentum the total momentum after an interaction is equal to the total momentum before system try to choose one whose momentum will be conserved explosion particles of a system move apart after a brief, intense interaction, opposite of a collision perfect inelastic collision a collision in which two objects stick together and move with a common final velocity angular momentum momentum of a particle in circular motion changes as the direction of motion changes; the product of rotational inertia and rotational velocity Law of Conservation of Angular Momentum angular momentum of a rotating object subject to no external torque is constant total angular momentum sum of the angular momenta of all the objects in the system total energy the sum of different energies present in the system transform energies of one kind can ____ into energy of another kind within a system energy transformations changes of energy within the system from one form to another energy transfer an exchange of energy between the system and environment work the mechanical transfer of energy to or from a system by pushing or pulling on it heat the nonmechanical transfer of energy from the environment to the system, or vice versa basic energy model shows how the energy model is modified to include energy transfers into and out of the system as well as energy transformations within the system isolated system (energy) no work is done on the system; total energy is conserved work done this is increased by larger displacements and stronger forces Joule unit of all forms of energy Work sign determined entirely by the angle theta between the force and the displacement total work the sum of the work done by each force translational kinetic energy kinetic energy of an object moving along a line or some other path rotational kinetic energy kinetic energy due to rotation rolling kinetic energy kinetic energy of this is always greater than that of a nonrotating object moving at the same speed potential energy stored energy that can be converted into other forms of energy conservative forces interaction forces that can store useful energy; gravity and elastic forces nonconservative forces energy cannot be stored; example: friction gravitational potential energy the higher an object is lifted, the greater this is ; only height matters elastic potential energy energy stored in a compressed or extended spring thermal energy sum of all atoms potential and kinetic energies mechanical energy kinetic, gravitational, elastic; conserved for an isolated system without friction perfectly elastic collision a collision in which mechanical energy is conserved power rate at which energy is transformed or transferred into or out of a system watt the unit of power electric -- thermal energy the energy isn't lost, but it is lost to our use efficiency reductions process limitations and fundamental limitations process limitations energy loss due to practical details of an energy transformation process fundamental limitations energy losses due to physical laws that cannot be circumvented calories units of thermal energy food calorie (Calorie) 1000 calories or 1 kcal human body efficiency 25% ideal gas the thermal energy of this is equal to the total kinetic energy of the moving atoms of gas ideal gas temperature measure of the average kinetic energy of the atoms that make up the gas absolute zero no temperature below this is possible zero degrees point at which the kinetic energy of atoms is zero heat energy transferred between two objects because of a temperature difference between them thermal equilibrium energy transfer continues until the atoms on both sides of the barrier have the same average kinetic energy First Law of Thermodynamics for systems in which only the thermal energy changes, the change in thermal energy is equal to the energy transferred into or out of the system as work, heat, or both thermodynamics the study of thermal energy energy reservoir an object or part of the environment so large that, its temperature does not noticeably change when heat is transferred between the system and the reservoir reservoir Q these quantities are positive energy-transfer diagram consists of a hot reservoir, a cold reservoir, and a bridge heat engine takes heat energy from hot reservoir, turns some into useful work, and exhausts the balance as waste heat in the cold reservoir heat pump transferring heat energy from a cold reservoir to a hot reservoir irreversible process spontaneous transfer of heat from hot to cold is an example entropy the probability that a certain state of a system will occur; increases as two systems with initially different temperatures move toward thermal equilibrium Second Law of Thermodynamics entropy of an isolated system never decreases; entropy either increases, until the system reaches equilibrium or, stays the same if the system is already in equilibrium