PHYS 250 final Conceptual questions
with complete Solutions 100%
PHYS 250 final Conceptual questions
with complete Solutions 100%
Consider two children sitting on a merry-go-round, with one closer to the outer edge and
one closer to the center. Which child has a greater angular speed? - ANSWER-They
both have the same angular speed. The outside child would move a larger distance
each rotation, so his linear speed would be larger but we are asking about angular
velocity.
There are two kinds of acceleration that can occur in rotational motion - tangential and
centripetal. What best describes the difference between these two kinds of
acceleration? - ANSWER-Centripetal acceleration is towards the center, while
tangential is along the edge of the circle.
Two ladybugs of the same mass are on a record that is on a record player. The record
player is turned on and it reaches a constant velocity. If the male ladybug is all the way
at the edge and the female ladybug is halfway between the center and the edge, what
can be said about their moments of inertia? - ANSWER-The male ladybug's moment of
inertia is four times that of the female's bc I=r^2
Consider two equal masses M attached to the ends of massless rods, of length R, as
shown in the figure. Treat the two masses as point masses, each located at a distance
R from the point where the rods touch. What is the moment of inertia of this system,
about an axis perpendicular to the page and passing through the point where the rods
touch? - ANSWER-2MR^2 bc I=MR^2
Consider the ball shown in the figure, moving in a circle. What is the direction of the
angular momentum of the ball? - ANSWER-Out of the page. Angular momentum (L) =
right hand rule
An ice skater is spinning with her arms out and is not being acted upon by an external
torque. - ANSWER-for the following terms
a. When she pulls her arms in close to her body what happens to her angular
momentum? - ANSWER-it remains unchanged bc angular momentum doesn't change if
there is no external torque acting on her
b. When she pulls her arms in, what happens to her moment of inertia? - ANSWER-It
decreases bc some of her M has moved closer to her body (I = MR^2)
c. What happens to her angular speed when she pulls her arms in? - ANSWER-it
increases
with complete Solutions 100%
PHYS 250 final Conceptual questions
with complete Solutions 100%
Consider two children sitting on a merry-go-round, with one closer to the outer edge and
one closer to the center. Which child has a greater angular speed? - ANSWER-They
both have the same angular speed. The outside child would move a larger distance
each rotation, so his linear speed would be larger but we are asking about angular
velocity.
There are two kinds of acceleration that can occur in rotational motion - tangential and
centripetal. What best describes the difference between these two kinds of
acceleration? - ANSWER-Centripetal acceleration is towards the center, while
tangential is along the edge of the circle.
Two ladybugs of the same mass are on a record that is on a record player. The record
player is turned on and it reaches a constant velocity. If the male ladybug is all the way
at the edge and the female ladybug is halfway between the center and the edge, what
can be said about their moments of inertia? - ANSWER-The male ladybug's moment of
inertia is four times that of the female's bc I=r^2
Consider two equal masses M attached to the ends of massless rods, of length R, as
shown in the figure. Treat the two masses as point masses, each located at a distance
R from the point where the rods touch. What is the moment of inertia of this system,
about an axis perpendicular to the page and passing through the point where the rods
touch? - ANSWER-2MR^2 bc I=MR^2
Consider the ball shown in the figure, moving in a circle. What is the direction of the
angular momentum of the ball? - ANSWER-Out of the page. Angular momentum (L) =
right hand rule
An ice skater is spinning with her arms out and is not being acted upon by an external
torque. - ANSWER-for the following terms
a. When she pulls her arms in close to her body what happens to her angular
momentum? - ANSWER-it remains unchanged bc angular momentum doesn't change if
there is no external torque acting on her
b. When she pulls her arms in, what happens to her moment of inertia? - ANSWER-It
decreases bc some of her M has moved closer to her body (I = MR^2)
c. What happens to her angular speed when she pulls her arms in? - ANSWER-it
increases
