Wgu physics Wgu physics
Study this set o nline at: https://www.cram.co m/flashcards/wgu-physics-5823329
Angul ar momentum Back (D ef i ni ti on)
T angenti al speed T he l i near speed tangent to a curved path, such as i n ci rcul ar moti on.
T he number of rotati ons or revol uti ons per uni t of ti me; of ten measured i n rotati ons
Rotati onal speed or revol uti ons per second or per mi nute. (Sci enti sts usual l y measure i t i n radi ans per
second.)
T hat property of an obj ect that measures i ts resi stance to any change i n i ts state of
Rotati onal i nerti a rotati on: i f at rest, the body tends to remai n at rest; i f rotati ng, i t tends to remai n
rotati ng and wi l l conti nue to do so unl ess acted upon by an external net torque.
,Wgu physics Wgu physics
Study this set o nline at: https://www.cram.co m/flashcards/wgu-physics-5823329
T orque T he product of f orce and l ever-arm di stance, whi ch tends to produce
T orque rotati on.
T orque = l ever arm × f orce
T he average posi ti on of the mass of an obj ect. T he CM moves as i f al l the external
Center of mass (CM)
f orces acted at thi s poi nt.
T he average posi ti on of wei ght or the si ngl e poi nt associ ated wi th an obj ect
Center of gravi ty (CG)
where the f orce of gravi ty can be consi dered to act.
E qui l i bri um T he state of an obj ect i n whi ch i t i s not acted upon by a net f orce or a net torque.
,Wgu physics Wgu physics
Study this set o nline at: https://www.cram.co m/flashcards/wgu-physics-5823329
A f orce di rected toward a f i xed poi nt,usual l y the cause of ci rcul ar moti on:
Centri petal f orce
F = mv2/r
An outward f orce apparent i n a rotati ng f rame of ref erence. I t i s apparent
Centri f ugal f orce (f i cti ti ous) i n the sense that i t i s not part of an i nteracti on but i s a resul t of
rotati on—wi th no reacti on-f orce counterpart.
T he product of a body’s rotati onal i nerti a and rotati onal vel oci ty about a
parti cul ar axi s. F or an obj ect that i s smal l compared wi th the radi al di stance, i t
Angul ar momentum
can be expressed as the product of mass, speed, and the radi al di stance of
rotati on.
When no external torque acts on an obj ect or a system of obj ects, no change of
angul ar momentum can occur. H ence, the angul ar momentum bef ore an event
Conservati on of angul ar momentum
i nvol vi ng onl y i nternal torques or no torques i s equal to the angul ar momentum af ter
the event.
, Wgu physics Wgu physics
Study this set o nline at: https://www.cram.co m/flashcards/wgu-physics-5823329
Law of uni versal gravi tati on E very body i n the uni verse attracts every other body
wi th a f orce that, f or two bodi es, i s di rectl y proporti onal to the product of thei r
Law of uni versal gravi tati on
masses and i nversel y proporti onal to the square of the di stance separati ng them:
F equal s G m sub 1 m sub 2 over d to the 2 power
T he oval path f ol l owed by a satel l i te. T he sum of the di stances f rom any poi nt on
the path to two poi nts cal l ed f oci i s a constant. When the f oci are together at one
E l l i pse
poi nt, the el l i pse i s a ci rcl e. As the f oci get f arther apart, the el l i pse becomes
more “eccentri c.
Kepl er’s l aws Law 1: T he path of each pl anet around the Sun i s an el l i pse wi th
the Sun at one f ocus.
Law 2: T he l i ne f rom the Sun to any pl anet sweeps out equal areas of space i n
Kepl er’s l aws
equal ti me i nterval s.
Law 3: T he square of the orbi tal peri od of a pl anet i s di rectl y proporti onal to the
cube of the average di stance of the pl anet f rom the Sun (T 2 ∼ r3 f or al l pl anets).
E scape speed T he speed that a proj ecti l e, space probe, or si mi l ar obj ect must
E scape speed reach to escape the gravi tati onal i nf l uence of E arth or of another cel esti al body
to whi ch i t i s attracted.
Study this set o nline at: https://www.cram.co m/flashcards/wgu-physics-5823329
Angul ar momentum Back (D ef i ni ti on)
T angenti al speed T he l i near speed tangent to a curved path, such as i n ci rcul ar moti on.
T he number of rotati ons or revol uti ons per uni t of ti me; of ten measured i n rotati ons
Rotati onal speed or revol uti ons per second or per mi nute. (Sci enti sts usual l y measure i t i n radi ans per
second.)
T hat property of an obj ect that measures i ts resi stance to any change i n i ts state of
Rotati onal i nerti a rotati on: i f at rest, the body tends to remai n at rest; i f rotati ng, i t tends to remai n
rotati ng and wi l l conti nue to do so unl ess acted upon by an external net torque.
,Wgu physics Wgu physics
Study this set o nline at: https://www.cram.co m/flashcards/wgu-physics-5823329
T orque T he product of f orce and l ever-arm di stance, whi ch tends to produce
T orque rotati on.
T orque = l ever arm × f orce
T he average posi ti on of the mass of an obj ect. T he CM moves as i f al l the external
Center of mass (CM)
f orces acted at thi s poi nt.
T he average posi ti on of wei ght or the si ngl e poi nt associ ated wi th an obj ect
Center of gravi ty (CG)
where the f orce of gravi ty can be consi dered to act.
E qui l i bri um T he state of an obj ect i n whi ch i t i s not acted upon by a net f orce or a net torque.
,Wgu physics Wgu physics
Study this set o nline at: https://www.cram.co m/flashcards/wgu-physics-5823329
A f orce di rected toward a f i xed poi nt,usual l y the cause of ci rcul ar moti on:
Centri petal f orce
F = mv2/r
An outward f orce apparent i n a rotati ng f rame of ref erence. I t i s apparent
Centri f ugal f orce (f i cti ti ous) i n the sense that i t i s not part of an i nteracti on but i s a resul t of
rotati on—wi th no reacti on-f orce counterpart.
T he product of a body’s rotati onal i nerti a and rotati onal vel oci ty about a
parti cul ar axi s. F or an obj ect that i s smal l compared wi th the radi al di stance, i t
Angul ar momentum
can be expressed as the product of mass, speed, and the radi al di stance of
rotati on.
When no external torque acts on an obj ect or a system of obj ects, no change of
angul ar momentum can occur. H ence, the angul ar momentum bef ore an event
Conservati on of angul ar momentum
i nvol vi ng onl y i nternal torques or no torques i s equal to the angul ar momentum af ter
the event.
, Wgu physics Wgu physics
Study this set o nline at: https://www.cram.co m/flashcards/wgu-physics-5823329
Law of uni versal gravi tati on E very body i n the uni verse attracts every other body
wi th a f orce that, f or two bodi es, i s di rectl y proporti onal to the product of thei r
Law of uni versal gravi tati on
masses and i nversel y proporti onal to the square of the di stance separati ng them:
F equal s G m sub 1 m sub 2 over d to the 2 power
T he oval path f ol l owed by a satel l i te. T he sum of the di stances f rom any poi nt on
the path to two poi nts cal l ed f oci i s a constant. When the f oci are together at one
E l l i pse
poi nt, the el l i pse i s a ci rcl e. As the f oci get f arther apart, the el l i pse becomes
more “eccentri c.
Kepl er’s l aws Law 1: T he path of each pl anet around the Sun i s an el l i pse wi th
the Sun at one f ocus.
Law 2: T he l i ne f rom the Sun to any pl anet sweeps out equal areas of space i n
Kepl er’s l aws
equal ti me i nterval s.
Law 3: T he square of the orbi tal peri od of a pl anet i s di rectl y proporti onal to the
cube of the average di stance of the pl anet f rom the Sun (T 2 ∼ r3 f or al l pl anets).
E scape speed T he speed that a proj ecti l e, space probe, or si mi l ar obj ect must
E scape speed reach to escape the gravi tati onal i nf l uence of E arth or of another cel esti al body
to whi ch i t i s attracted.
