PHYS 1301 WTC Final Exam questions with correct answers.

PHYS 1301 WTC Final Exam questions with
correct answers
Two |points |are |on |a |disk |that |rotates |about |an |axis |perpendicular |to |the |plane |of |the |disk |at |its |
center. |point |BB |is |9 |times |as |far |from |the |axis |as |point |AA.

Part |A

If |the |linear |speed |of |point |BB |is |VV, |then |the |linear |speed |of |point |AA |is |- |VERIFIED |ANSWER✔✔-V/9
|(second |largest |number |divided |by)




A |disk |starts |from |rest |and |has |a |constant |angular |acceleration.

Part |A

If |it |takes |time |TT |to |make |its |first |revolution, |in |time |6TT |(starting |from |rest) |the |disk |will |make |- |
VERIFIED |ANSWER✔✔-36 |revolutions |(second |largest)



Two |unequal |masses |mm |and |2m2m |are |attached |to |a |thin |bar |of |negligible |mass |that |rotates |about |
an |axis |perpendicular |to |the |bar. |When |mm |is |a |distance |2d2d |from |the |axis |and |2m2m |is |a |distance |
dd |from |the |axis, |the |moment |of |inertia |of |this |combination |is |II.

Part |A

Part |complete

If |the |masses |are |now |interchanged, |the |moment |of |inertia |will |be |- |VERIFIED |ANSWER✔✔-2/3 |I



A |thin |uniform |bar |has |a |moment |of |inertia |II |about |an |axis |perpendicular |to |it |through |its |center.

Part |A

If |both |the |mass |and |length |of |this |bar |are |doubled, |its |moment |of |inertia |about |the |same |axis |will |
be |- |VERIFIED |ANSWER✔✔-8I |(largest |number)



Two |small |objects |of |equal |weight |are |attached |to |the |ends |of |a |thin |weightless |bar |that |spins |about |
an |axis |perpendicular |to |the |bar |at |its |center. |Each |mass |is |a |distance |dd |from |the |axis |of |rotation. |
The |system |spins |at |a |rate |so |that |its |kinetic |energy |is |KK.

Part |A

, If |both |masses |are |now |moved |closer |in |so |that |each |is |dd/6 |from |the |rotation |axis, |while |the |
angular |velocity |does |not |change, |the |kinetic |energy |of |the |system |will |be |- |VERIFIED |ANSWER✔✔-
1/36 |KK. |(largest |number |divided)



When |a |wheel |turns |through |one |complete |rotation, |the |angle |(in |radians) |that |it |has |turned |through
|is |closest |to |- |VERIFIED |ANSWER✔✔-6 |radians




A |person |pushes |vertically |downward |with |force |P⃗ |P→ |on |a |lever |of |length |LL |that |is |inclined |at |an |
angle |θθ |above |the |horizontal |as |shown |in |the |figure |below |(Figure |1).

Figure1 |of |1

Part |A

The |torque |that |the |person's |push |produces |about |point |AA |is |- |VERIFIED |ANSWER✔✔-P |L |cos(theta)



String |is |wrapped |around |the |outer |rim |of |a |solid |uniform |cylinder |that |is |free |to |rotate |about |a |
frictionless |axle |through |its |center. |When |the |string |is |pulled |with |a |force |PP |tangent |to |the |rim, |it |
gives |the |cylinder |an |angular |acceleration |αα.

Part |A

If |the |cylinder |had |four |times |the |radius, |but |everything |else |was |the |same, |the |angular |acceleration |
would |be |- |VERIFIED |ANSWER✔✔-a/4



A |ball |of |mass |0.500 |kgkg |is |whirled |in |a |horizontal |circle |at |the |end |of |a |light |string |75.0 |cmcm |long |
at |a |speed |of |3.00 |m/sm/s.

Part |A

If |the |string |is |lengthened |to |2.00 |mm |while |the |ball |is |being |twirled, |then |the |speed |of |the |ball |will |
now |be |- |VERIFIED |ANSWER✔✔-.75(3)=2x |(ans: |1.13)



A |heavy |solid |disk |rotating |freely |and |slowed |only |by |friction |applied |at |its |outer |edge |takes |60 |
seconds |to |come |to |a |stop. |If |the |disk |had |twice |the |radius |and |twice |the |mass, |but |the |frictional |
force |remained |the |same, |the |time |it |would |it |take |the |wheel |to |come |to |a |stop |from |the |same |initial
|rotational |speed |is |- |VERIFIED |ANSWER✔✔-240 |(second |largest)




While |the |turntable |is |being |accelerated, |the |person |suddenly |extends |her |legs. |What |happens |to |the
|turntable? |- |VERIFIED |ANSWER✔✔-acceleration |decreases