PHYS 220 - Exam 2 questions with correct answers

PHYS 220 - Exam 2 questions with correct
answers
when |is |work |positive? |- |VERIFIED |ANSWER✔✔-when |force |and |displacement |are |in |the |same |
direction; |angle |is |less |than |90 |degrees



when |is |work |negative? |- |VERIFIED |ANSWER✔✔-when |the |force |is |in |the |opposite |direction |of |
displacement; |angle |is |greater |than |90 |degrees



what |does |torque |indicate? |- |VERIFIED |ANSWER✔✔-rotational |motion



what |must |be |true |for |a |system |in |static |equilibrium? |- |VERIFIED |ANSWER✔✔-the |net |forces |on |all |
parts |must |be |zero |(ex: |the |net |force |on |each |pulley |must |equal |zero)



what |is |true |of |the |center |of |mass? |- |VERIFIED |ANSWER✔✔-it |is |weighted |towards |the |heavier |part |
of |the |object

CM |= |(mx |+ |mx |+ |mx...) |/ |(m |+ |m |+ |m...)



positive |angular |momentum |- |VERIFIED |ANSWER✔✔-counterclockwise



negative |angular |momentum |- |VERIFIED |ANSWER✔✔-clockwise



when |is |torque |positive? |- |VERIFIED |ANSWER✔✔-if |force |would |cause |system |to |rotate |
counterclockwise



when |is |torque |negative? |- |VERIFIED |ANSWER✔✔-if |force |would |cause |system |to |rotate |clockwise



elastic |collision |- |VERIFIED |ANSWER✔✔-momentum |and |kinetic |energy |are |conserved

ex: |two |objects |colliding |and |bouncing |off |one |another