\"border: 0px currentColor; height: 0px; left: 0px; margin: 0px; padding: 0px; p
ID: 2111816 • Letter: #
Question
"border: 0px currentColor; height: 0px; left: 0px; margin: 0px; padding: 0px; position: absolute; top: 43px; width: 737px; z-index: 101"
id="MathJax_MSIE_Frame">
"border: 0px currentColor; height: 0px; left: 0px; margin: 0px; padding: 0px; position: absolute; top: 43px; width: 737px; z-index: 101"
id="MathJax_MSIE_Frame">
"border: 0px currentColor; height: 0px; left: 0px; margin: 0px; padding: 0px; position: absolute; top: 7px; width: 737px; z-index: 101"
id="MathJax_MSIE_Frame">
"color: black; letter-spacing: -0.05pt; font-size: 11pt;">A ball of
mass m falls from height h,to height
hf near the
"color: black; letter-spacing: 0.1pt; font-size: 11pt;">surface of
the Earth, as shown at right. When the ball passes
it has a speed
vf. Ignore air resistance, and assume that
any
"color: black; letter-spacing: -0.05pt; font-size: 11pt;">changes
in kinetic energy of the Earth are negligible.
In this problem,
you will analyze this situation by considering
"color: black; font-size: 11pt;">two different systems: system BE
(the ball and the Earth) and
"color: black; letter-spacing: -0.05pt; font-size: 11pt;">system B
(the ball alone).
"MsoNormal">
"color: black; letter-spacing: -0.05pt; font-size: 11pt;">a.Consider
system BE, consisting of the ball and the Earth.
"background: white; margin: 8.15pt 40.3pt 0pt 46.3pt; line-height: 12pt; text-indent: -14.15pt; mso-line-height-rule: exactly;"
class="MsoNormal">
"color: black; letter-spacing: -0.1pt; font-size: 11pt;">i.As the
ball falls from h{ to hf, does
the total energy of system BE increase, decrease, or
"color: black; letter-spacing: -0.05pt; font-size: 11pt;">stay the
same?)
"color: black; letter-spacing: -0.05pt; font-size: 11pt;">Explain
by considering the net work by external forces on system
BE.
class="MsoNormal">
"color: black; font-size: 11pt;">ii.Consider the following
discussion:
class="MsoNormal">
'color: black; letter-spacing: 0.05pt; font-family: "Arial","sans-serif"; font-size: 9.5pt;'>
Student 1:"The changes to system BE are all internal, so its
gravitational potential
"background: white; margin: 0.25pt 0.8in 0pt 103.7pt; line-height: 11.5pt; mso-line-height-rule: exactly;"
class="MsoNormal">
'color: black; font-family: "Arial","sans-serif"; font-size: 9.5pt;'>
energy doesn't change. Since the kinetic energy of the ball
increases, the total energy of system BE increases."
"background: white; margin: 8.9pt 0.8in 0pt 103.45pt; line-height: 11.75pt; text-indent: -53.3pt; mso-line-height-rule: exactly;"
class="MsoNormal">
'color: black; letter-spacing: 0.1pt; font-family: "Arial","sans-serif"; font-size: 9.5pt;'>
Student 2:"I think that the change in potential energy of the
system is zero because
'color: black; font-family: "Arial","sans-serif"; font-size: 9.5pt;'>
the distance the ball moves is small compared to the size of the
earth. The change in total
energy of system BE is equal to the change in kinetic energy
of the
ball."
"MsoNormal">
"color: black; letter-spacing: 0.05pt; font-size: 11pt;">Identify
the incorrect statements made by both students. Explain.
"background: white; margin: 50.15pt 60.5pt 0pt 49.45pt; line-height: 12pt; text-indent: -0.25in; mso-line-height-rule: exactly;"
class="MsoNormal">
"color: black; letter-spacing: -0.05pt; font-size: 11pt;">iii.
Write an expression for each of the following quantities in terms
of the given variables
"color: black; font-size: 11pt;">and any physical constants. If any
of these are zero, state so explicitly.
"background: white; margin: 0in 0in 0pt 48.95pt; line-height: 26.65pt; text-indent: 0in; mso-line-height-rule: exactly; tab-stops: 58.1pt; mso-list: l0 level1 lfo1;"
class="MsoNormal">
'color: black; font-size: 11pt; mso-fareast-font-family: "Times New Roman";'>
%u2022
'color: black; font-size: 11pt; mso-fareast-font-family: "Times New Roman";'>the
change in kinetic energy of system BE
"background: white; margin: 0in 0in 0pt 48.95pt; line-height: 26.65pt; text-indent: 0in; mso-line-height-rule: exactly; tab-stops: 58.1pt; mso-list: l0 level1 lfo1;"
class="MsoNormal">
'color: black; font-size: 11pt; mso-fareast-font-family: "Times New Roman";'>
%u2022
'color: black; font-size: 11pt; mso-fareast-font-family: "Times New Roman";'>the
change in potential energy of system BE
"background: white; margin: 0.25pt 181.45pt 0pt 30.95pt; line-height: 26.65pt; text-indent: 0.25in; mso-line-height-rule: exactly; tab-stops: 58.1pt; mso-list: l0 level1 lfo1;"
class="MsoNormal">
'color: black; font-size: 11pt; mso-fareast-font-family: "Times New Roman";'>
%u2022
'color: black; letter-spacing: -0.05pt; font-size: 11pt; mso-fareast-font-family: "Times New Roman";'>the
net external work by external forces on system
BE
'color: black; letter-spacing: 0.05pt; font-size: 11pt; mso-fareast-font-family: "Times New Roman";'>iv.
Write an equation that relates the expressions above.
"background: white; margin: 47.3pt 40.3pt 0pt 48.7pt; line-height: 12pt; text-indent: -17.75pt; mso-line-height-rule: exactly;"
class="MsoNormal">
"color: black; letter-spacing: 0.05pt; font-size: 11pt;">v.Solve
your equation from part iv for the final speed of the ball. Is your
result consistent
"color: black; letter-spacing: -0.05pt; font-size: 11pt;">with what
you would obtain using kinematics and your knowledge of the
acceleration due
"color: black; letter-spacing: 0.05pt; font-size: 11pt;">to gravity
near the Earth's surface? If not, resolve the
inconsistency.
class="MsoNormal">
"color: black; font-size: 11pt;">b.Consider the system of the ball
only, system B.
"background: white; margin: 8.65pt 0in 0pt 83.5pt; line-height: 11.75pt; text-indent: -0.25in; mso-line-height-rule: exactly;"
class="MsoNormal">
"color: black; letter-spacing: -0.1pt; font-size: 11pt;">i.As the
ball falls from h{ to hf, does
the total energy of system B increase, decrease, or
stay the
same?
"color: black; font-size: 11pt;">Explain by considering the net
external workon system B.
"background: white; margin: 51.35pt 0in 0pt 83.75pt; line-height: 12pt; text-indent: -18.25pt; mso-line-height-rule: exactly;"
class="MsoNormal">
"color: black; letter-spacing: -0.05pt; font-size: 11pt;">ii.Write
an expression for each of the following quantities in terms of the
given variables and any physical constants.
"background: white; margin: 0in 0in 0pt 83.5pt; line-height: 26.4pt; text-indent: 0in; mso-line-height-rule: exactly; tab-stops: 92.4pt; mso-list: l0 level1 lfo2;"
class="MsoNormal">
'color: black; font-size: 11pt; mso-fareast-font-family: "Times New Roman";'>
%u2022
'color: black; letter-spacing: -0.05pt; font-size: 11pt; mso-fareast-font-family: "Times New Roman";'>the
net external work on system B
"background: white; margin: 0in 0in 0pt 83.5pt; line-height: 26.4pt; text-indent: 0in; mso-line-height-rule: exactly; tab-stops: 92.4pt; mso-list: l0 level1 lfo2;"
class="MsoNormal">
'color: black; font-size: 11pt; mso-fareast-font-family: "Times New Roman";'>
%u2022
'color: black; letter-spacing: -0.05pt; font-size: 11pt; mso-fareast-font-family: "Times New Roman";'>the
change in kinetic energy of system B
"background: white; margin: 0.25pt 0in 0pt 83.5pt; line-height: 26.4pt; text-indent: 0in; mso-line-height-rule: exactly; tab-stops: 92.4pt; mso-list: l0 level1 lfo2;"
class="MsoNormal">
'color: black; font-size: 11pt; mso-fareast-font-family: "Times New Roman";'>
%u2022
'color: black; letter-spacing: -0.05pt; font-size: 11pt; mso-fareast-font-family: "Times New Roman";'>the
change in potential energy of system B
"MsoNormal">
"color: black; letter-spacing: 0.05pt; font-size: 11pt;">iii.
Consider the following true statement about potential
energy:
"background: white; margin: 8.9pt 0in 0pt 83.05pt; line-height: 11.75pt; mso-line-height-rule: exactly;"
class="MsoNormal">
'color: black; letter-spacing: 0.1pt; font-family: "Arial","sans-serif"; font-size: 9pt;'>
"Changes in potential energy are associated with changes in shape
of a system, or changes
'color: black; letter-spacing: 0.3pt; font-family: "Arial","sans-serif"; font-size: 9pt;'>
in relative positions of the objects that make up the system.
A system consisting of a
'color: black; letter-spacing: 0.1pt; font-family: "Arial","sans-serif"; font-size: 9pt;'>
single object that undergoes no change in shape or other internal
changes does not have a change in potential energy."
"background: white; margin: 8.4pt 0in 0pt 83.05pt; line-height: 12pt; mso-line-height-rule: exactly;"
class="MsoNormal">
"color: black; letter-spacing: -0.05pt; font-size: 11pt;">Explain
how your answer to the third bullet of part b.ii is consistent with
this statement.
"color: black; font-size: 11pt;">If it is not consistent, how could
you change it to make it consistent?
class="MsoNormal">iv.
Write an equation that relates the three expressions from part
b.ii.
class="MsoNormal">
"color: black; letter-spacing: -0.05pt; font-size: 11pt;">v.Solve
the equation from part b.iv for the final speed of the
ball.
"background: white; margin: 71.75pt 0in 0pt 63.85pt; line-height: 11.5pt; text-indent: -17.5pt; mso-line-height-rule: exactly;"
class="MsoNormal">
"color: black; font-size: 11pt;">c.Check that your answer to part
b.v is consistent with your answer to part a.v. If not, resolve the
inconsistency.
'font-family: "Times New Roman","serif"; font-size: 10pt; mso-fareast-font-family: "Times New Roman"; mso-fareast-theme-font: minor-fareast; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;'>
"page-break-before: always; mso-break-type: section-break;" clear=
"all" />
"background: white; margin: 13.9pt 0in 0pt 75.4pt; text-indent: 16.3pt;"
class="MsoNormal">
"color: black; letter-spacing: -0.2pt; font-size: 11.5pt;">d.In
summary, based on work and energy considerations:
"background: white; margin: 9.1pt 42.25pt 0pt 125.75pt; line-height: 12pt; text-indent: -17.75pt; mso-line-height-rule: exactly;"
class="MsoNormal">
"color: black; letter-spacing: -0.25pt; font-size: 11.5pt;">i.Can
the Earth affect the total energy of system BE (i.e., a
system that includes the Earth)? Explain.
"background: white; margin: 50.65pt 40.3pt 0pt 125.75pt; line-height: 11.75pt; text-indent: -0.25in; mso-line-height-rule: exactly;"
class="MsoNormal">
"color: black; letter-spacing: 0.15pt; font-size: 10.5pt;">ii.Can
the Earth affect the total energy of system B (i.e., a
system that does not include the
"color: black; letter-spacing: 0.35pt; font-size: 10.5pt;">Earth)?
Explain.
Explanation / Answer
can you please explain what the question is about?
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.