exam 2

Question 1

energy

Answer 1

the ability to do work

Question 2

kinetic energy

Answer 2

energy of motion

Question 3

work energy principle

Answer 3

the net work done on an object equals the change in kinetic energy of that object

Question 4

potential energy

Answer 4

energy associated with forces that depend on the position or configuration of objects

Question 5

conservative forces

Answer 5

work done by the force in moving an object from one position to another depends only on the two positions and not the path taken; associated with potential energy

Question 6

nonconservative forces

Answer 6

work done by them is dependent on the path taken; potential energy cannot be defined

Question 7

law of conservation of energy

Answer 7

energy can be transformed from one type to another but the total energy of the system remains constant

Question 8

power

Answer 8

the rate at which work is done or energy is transformed

Question 9

linear momentum

Answer 9

the product of mass times velocity

Question 10

law of conservation of momentum

Answer 10

when the net forces on a system of objects is 0, the total momentum remains constant

Question 11

impulse

Answer 11

average force times the time interval, equal to the change in momentum

Question 12

elastic collision

Answer 12

total momentum and total energy are both conserved

Question 13

inelastic collision

Answer 13

momentum is conserved but total energy is not, total inelastic occurs when objects stick together post collision

Question 14

center of mass

Answer 14

the point on an extended object at which the net force can be considered to act for the purpose of determining translational motion as a whole

Question 15

angular velocity

Answer 15

the rate of change of angular position the same at any point of a rigid object rotating about a fixed axis

Question 16

angular acceleration

Answer 16

the rate of change of angular velocity

Question 17

moment of inertia

Answer 17

depends on the mass of the object and how it is distributed relative to the axis of rotation

Question 18

law of conservation of angular momentum

Answer 18

if the net torque on an object is zero the angular momentum is constant

Question 19

statics

Answer 19

the subject concerned with the determination of the forces within a structure at rest

Question 20

equilibrium

Answer 20

state of an object at rest, the vector sum of all forces and torques must be 0

Question 21

Hooke’s law

Answer 21

the change in length of an object is proportional to the applied force

Question 22

density

Answer 22

mass per unit volume

Question 23

specific gravity

Answer 23

the ratio of the density of the material to the density of water

Question 24

pascals principle

Answer 24

says that an external pressure applied to a contained fluid is transmitted through that fluid

Question 25

Archimedes’ principle

Answer 25

states that an object submerged wholly or partially in a fluid is buoyed up by a force equal to the weight of fluid it displaces

Question 26

laminar flow

Answer 26

streamline; layers of fluid move smoothly and regularly along paths around an object

Question 27

turbulent flow

Answer 27

flow is not smooth and regular but is characterized by irregularly shaped whirlpools

Question 28

equation of continuity

Answer 28

states that for an incompressible fluid flowing in an enclosed tube, the product of the velocity of flow and the cross sectional area of the tube remains constant
Av=constant

Question 29

Bernoulli’s principle

Answer 29

tells us where the velocity of a fluid is high, the pressure is low and vice versa