Physics 121 Final Exam Review BYU IS
Question and answers 100% correct
2025
how many standard balloons can fit into a minivan? - correct answer ✔about
200
A standard helium balloon is of the order of a foot across. The inside of a
minivan is about 5 feet across by 4 feet high by 8 feet long. That is a volume
of about 200 cubic feet. Probably only about 2/3 of that can be used for
balloons, so 200 is probably too high, but it is closer than any of the other
answers.
carrying bucket at constant speed, what work is done? - correct answer
✔none, it's a constant speed so no CHANGE in kinetic energy
also it wasn't lifted up, so the gravitational energy didn't change since
gravitational force was perpendicular to the displacement
unstable equilibrium point is where - correct answer ✔where the potential
energy is at a maximum
neutral equilibrium is where? - correct answer ✔where it is flat no curvature
how to take a dot product? - correct answer ✔i*i - j*j = 1 number
net work is equal to what?? - correct answer ✔CHANGE in kinetic energy.
think about v2 in the kinetic energy theorem and remember that !
, conservative forces include:
nonconservative forces include:
definition - correct answer ✔gravity conservative, electric elastic,
air resistance nonconservative, friction applied tension push and pull
conservative forces have NO NET WORK over a closed loop, equal work
between points irrespective of path, always has potential energy function
nonconservative forces do more work over longer path distances and do have
net work over closed loops
point of stable equilibrium definition - correct answer ✔a point where a force
will always bring it back to that no matter what, like a ball in a bowl it will
always make it back to the bottom, or a stretchy spring will always make it
back to its resting state.
what is impulse?
what is momentum equation? - correct answer ✔impulse is change in
momentum
momentum is mass times velocity
in collisions, what is always conserved and what might not be? - correct
answer ✔momentum is always conserved even if the collision isn't head on
kinetic energy sometimes is and sometimes isn't
cross product is perpendicular to ? - correct answer ✔both vectors crossed!
cross two vectors with only i and j or whatnot - correct answer ✔magnitude a
* magnitude b * sin theta between them
angular acceleration:
Question and answers 100% correct
2025
how many standard balloons can fit into a minivan? - correct answer ✔about
200
A standard helium balloon is of the order of a foot across. The inside of a
minivan is about 5 feet across by 4 feet high by 8 feet long. That is a volume
of about 200 cubic feet. Probably only about 2/3 of that can be used for
balloons, so 200 is probably too high, but it is closer than any of the other
answers.
carrying bucket at constant speed, what work is done? - correct answer
✔none, it's a constant speed so no CHANGE in kinetic energy
also it wasn't lifted up, so the gravitational energy didn't change since
gravitational force was perpendicular to the displacement
unstable equilibrium point is where - correct answer ✔where the potential
energy is at a maximum
neutral equilibrium is where? - correct answer ✔where it is flat no curvature
how to take a dot product? - correct answer ✔i*i - j*j = 1 number
net work is equal to what?? - correct answer ✔CHANGE in kinetic energy.
think about v2 in the kinetic energy theorem and remember that !
, conservative forces include:
nonconservative forces include:
definition - correct answer ✔gravity conservative, electric elastic,
air resistance nonconservative, friction applied tension push and pull
conservative forces have NO NET WORK over a closed loop, equal work
between points irrespective of path, always has potential energy function
nonconservative forces do more work over longer path distances and do have
net work over closed loops
point of stable equilibrium definition - correct answer ✔a point where a force
will always bring it back to that no matter what, like a ball in a bowl it will
always make it back to the bottom, or a stretchy spring will always make it
back to its resting state.
what is impulse?
what is momentum equation? - correct answer ✔impulse is change in
momentum
momentum is mass times velocity
in collisions, what is always conserved and what might not be? - correct
answer ✔momentum is always conserved even if the collision isn't head on
kinetic energy sometimes is and sometimes isn't
cross product is perpendicular to ? - correct answer ✔both vectors crossed!
cross two vectors with only i and j or whatnot - correct answer ✔magnitude a
* magnitude b * sin theta between them
angular acceleration:
