PHYSICS 250 FINAL EXAMINATION TEST 2026
THEORY QUESTIONS AND COMPLETE
ANSWERS
◉ 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 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 family
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
◉ consider two equal masses M attached to the ends of massless
rods, of length R. 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
, ◉ 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
◉ 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. what happens to her rotational kinetic
energy 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. when she pulls her arms in close to her
body what happens to her angular velocity? Answer: it increases
THEORY QUESTIONS AND COMPLETE
ANSWERS
◉ 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 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 family
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
◉ consider two equal masses M attached to the ends of massless
rods, of length R. 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
, ◉ 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
◉ 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. what happens to her rotational kinetic
energy 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. when she pulls her arms in close to her
body what happens to her angular velocity? Answer: it increases
