PHY 111 FINAL EXAM QUESTIONS
AND ANSWERS
A-flatbed-truck-carrying-a-light-box-makes-a-sharp-turn-and-the-box-slides-off-the-truck-
bed.-In-what-direction-will-the-box-slide?---ans-✔✔along-the-tangent-to-its-circular-path
A-1.2-kg-rock-is-swung-around-on-a-string-in-a-vertical-circle-with-a-radius-of-0.85-m.-The-
minimum-speed-required-for-the-rock-at-the-top-of-the-circle-to-keep-it-in-it's-circular-path-
is---ans-✔✔2.9-m/s
If-the-distance-between-two-masses-is-doubled,-what-happens-to-the-gravitational-force-
between-the-masses?---ans-✔✔It-will-be-reduced-to-one-quarter-(Fg=1(1)(1)/2^2=1/4)
NASA-is-launching-a-satellite-with-mass-m-into-a-circular-orbit-with-radius-r-around-the-
Earth.-The-orbit-of-the-satellite-is-illustrated-in-the-figure-below(LOOK-AT-NOTES).-The-
velocity,-v,-of-the-satellite-is-shown-with-the-arrow.-Consider-the-following-arrows-and-
directions-(AGAIN-LOOK-AT-NOTES)-
-Which-arrow-is-in-the-direction-of-the-net-force-on-the-satellite?---ans-✔✔D.-IV
If-a-second-satellite-is-placed-in-a-larger-circular-orbit-than-the-first,-how-will-the-speeds-of-
the-satellites-compare?---ans-✔✔the-second-satellite-must-have-a-smaller-speed.
The-satellite-does-not-fall-down-to-the-earth-because---ans-✔✔they-have-a-sufficient-
horizontal-speed-to-move-around-the-earth-instead-of-falling-down,
A-student-sets-up-a-meterstick-resting-on-a-stand-at-the-80-cm-mark-and-held-in-place-by-
a-scale-attached-at-the-zero-cm-mark-as-shown-in-the-figure-below(NOTES!)A-mass,-M,-
is-then-attached-to-the-meter-stick-at-some-point-between-the-stand-and-the-scale.-
Assume-the-mass-of-the-meter-stick-is-negligible.-The-student-proceeds-to-measure-the-
force,-F,-shown-on-the-scale-for-different-values-of-mass-M-and-for-different-locations-of-
mass-M.-
--In-an-experiment,-the-student-places-a-mass-M-at-the-20-cm-mark-and-records-the-force-
measured-by-the-scale.-When-she-later-slides-the-same-mass-to-the-60-cm-mark,-what-
will-happen-to-the-force-measured-by-the-scale?---ans-✔✔the-force-will-be-reduced-to-one-
third.
AND ANSWERS
A-flatbed-truck-carrying-a-light-box-makes-a-sharp-turn-and-the-box-slides-off-the-truck-
bed.-In-what-direction-will-the-box-slide?---ans-✔✔along-the-tangent-to-its-circular-path
A-1.2-kg-rock-is-swung-around-on-a-string-in-a-vertical-circle-with-a-radius-of-0.85-m.-The-
minimum-speed-required-for-the-rock-at-the-top-of-the-circle-to-keep-it-in-it's-circular-path-
is---ans-✔✔2.9-m/s
If-the-distance-between-two-masses-is-doubled,-what-happens-to-the-gravitational-force-
between-the-masses?---ans-✔✔It-will-be-reduced-to-one-quarter-(Fg=1(1)(1)/2^2=1/4)
NASA-is-launching-a-satellite-with-mass-m-into-a-circular-orbit-with-radius-r-around-the-
Earth.-The-orbit-of-the-satellite-is-illustrated-in-the-figure-below(LOOK-AT-NOTES).-The-
velocity,-v,-of-the-satellite-is-shown-with-the-arrow.-Consider-the-following-arrows-and-
directions-(AGAIN-LOOK-AT-NOTES)-
-Which-arrow-is-in-the-direction-of-the-net-force-on-the-satellite?---ans-✔✔D.-IV
If-a-second-satellite-is-placed-in-a-larger-circular-orbit-than-the-first,-how-will-the-speeds-of-
the-satellites-compare?---ans-✔✔the-second-satellite-must-have-a-smaller-speed.
The-satellite-does-not-fall-down-to-the-earth-because---ans-✔✔they-have-a-sufficient-
horizontal-speed-to-move-around-the-earth-instead-of-falling-down,
A-student-sets-up-a-meterstick-resting-on-a-stand-at-the-80-cm-mark-and-held-in-place-by-
a-scale-attached-at-the-zero-cm-mark-as-shown-in-the-figure-below(NOTES!)A-mass,-M,-
is-then-attached-to-the-meter-stick-at-some-point-between-the-stand-and-the-scale.-
Assume-the-mass-of-the-meter-stick-is-negligible.-The-student-proceeds-to-measure-the-
force,-F,-shown-on-the-scale-for-different-values-of-mass-M-and-for-different-locations-of-
mass-M.-
--In-an-experiment,-the-student-places-a-mass-M-at-the-20-cm-mark-and-records-the-force-
measured-by-the-scale.-When-she-later-slides-the-same-mass-to-the-60-cm-mark,-what-
will-happen-to-the-force-measured-by-the-scale?---ans-✔✔the-force-will-be-reduced-to-one-
third.
