Physics 250 final exam With Complete
Solutions.
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
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.
An ice skater is spinning with her arms out and is not being acted upon by an external torque.
When she pulls her arms in close to her body what happens to her angular momentum? -
Answer It remains unchanged
An ice skater is spinning with her arms out and is not being acted upon by an external torque.
When she pulls her arms in, what happens to her moment of inertia? - Answer It decreases
An ice skater is spinning with her arms out and is not being acted upon by an external torque.
What happens to her angular speed when she pulls her arms in? - Answer It increases
An ice skater is spinning with her arms out and is not being acted upon by an external torque.
Solutions.
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
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.
An ice skater is spinning with her arms out and is not being acted upon by an external torque.
When she pulls her arms in close to her body what happens to her angular momentum? -
Answer It remains unchanged
An ice skater is spinning with her arms out and is not being acted upon by an external torque.
When she pulls her arms in, what happens to her moment of inertia? - Answer It decreases
An ice skater is spinning with her arms out and is not being acted upon by an external torque.
What happens to her angular speed when she pulls her arms in? - Answer It increases
An ice skater is spinning with her arms out and is not being acted upon by an external torque.
