Physics Ch 4

Question 0

Force

Answer 0

a push or a pull; a vector quantity (magnitude & direction)

Question 1

Dynamics

Answer 1

Considers the forces that affect the motion of moving objects & systems

Question 2

Free Body Diagram

Answer 2

technique used to illustrate all the external forces acting on a body

Question 3

Restoring force

Answer 3

force an object uses to pull itself back to its relaxed shape

Question 4

Newton’s 1st Law of Motion

Answer 4

a body at rest remains at rest, or if in motion, remains in motion at a constant velocity unless acted on by a net external force

Question 5

Inertia

Answer 5

the property of a body to remain at rest or to remain in motion with constant velocity

Question 6

Law of Inertia

Answer 6

Newton’s 1st law often called this

Question 7

Mass

Answer 7

inertia of an object measured by this

Question 8

Newton’s 2nd Law of Motion

Answer 8

mathematically states the cause and effect relationship between force and changes in motion; acceleration is proportional to net external force

Question 9

Acceleration

Answer 9

a change in velocity; net external force causes this

Question 10

External force

Answer 10

acts from outside the system of interest

Question 11

Friction

Answer 11

force that opposes the motion past each other of objects that are touching

Question 12

Net External Force

Answer 12

vector sum of all external forces

Question 13

Newton

Answer 13

SI unit of force

Question 14

weight (w)

Answer 14

net force on a falling object; gravitational force on an object from the nearest large body; a vector quantity; w = mg

Question 15

Free fall

Answer 15

when the net external force on an object is its weight

Question 16

Newton’s 3rd law of motion

Answer 16

whenever one body exerts a force on a 2nd body, the 1st body experiences a force that is equal in magnitude and opposite in direction to the force that it exerts

Question 17

thrust

Answer 17

reaction force

Question 18

Normal force

Answer 18

if the force supporting a load is perpendicular to the surface of contact between the load and its support (N)

Question 19

Tension

Answer 19

force along the length of a medium, especially a force carried by a flexible medium (ex. rope, cable)

Question 20

Real forces

Answer 20

forces with a physical origin

Question 21

Fictitious forces

Answer 21

those that occur because an observer is in an accelerating frame of reference

Question 22

Inertial frame of reference

Answer 22

one in which all forces are real and equivalently, one in which Newton’s laws have the simplest forms

Question 23

Carrier particles

Answer 23

fundamental particle of nature that is surrounded by a characteristic force field; photons are carriers of the electromagnetic force

Question 24

Force field

Answer 24

region in which a test particle will experience a force