Name: ________________________ Class: ___________________ Date: __________
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Unit 6 Week 2 Problem Set - AP Physics
Problems
Complete on lined paper. Show all your work. Circle your final answers.
1. Astronaut Bob (m=125kg) floats in space at a
center to center distance of 6.7 meters from
Astronaut Frank (m=95kg). Calculate the force of
attraction between the two astronauts.
9. Jupiter orbits the Sun with an orbital radius of
7.78 × 10 11 m. Given that the mass of the Sun is
2.00 × 1030 kg, calculate the orbital velocity of
Jupiter.
2. Planet Krypton was orbited by 2 moons. The
closest moon had a period of 41 days and orbited at
a radius of 6.5×108m. How far was the second
moon if it had a period of 87 days?
10. Calculate the force of gravitational attraction
between two spheres of mass 10.1 kg and 45.4 kg
that are 38.5 m apart.
11. Venus has radius 6.05 × 10 6 m and mass
4.87 × 10 24 kg. Calculate the value of acceleration
due to gravity on Venus’s surface.
3. At what altitude above the surface of the Earth
should a satelllite be placed to have a period of 250
minutes?
12. If Earth shrinks in size such that its shape and mass
remain the same, but the radius decreases to 0.21
times its original value, find the acceleration due to
gravity on its surface.
4. Planet X has a mass of 6.45×1024kg and a radius of
5.25×106m. What is the value of the gravitational
field strength at the surface of the planet? Give
your answer in terms of Earth’s surface gravity,
where g=9.8N/kg.
13. A satellite orbits Neptune 4000 km above its
surface. Given that the mass of Neptune is
1.02 × 10 26 kg and the radius of Neptune is
2.48 × 10 7 m, calculate the orbital speed of the
satellite.
5. Show how the constant of proportionality in
Kepler’s third law can be found by equating
gravitational force and the centripetal force in a
circular orbit.
6. A new moon is discovered orbiting Neptune with
an orbital speed of 9.11 × 10 3 m/s. Neptune’s mass
is 1.0 × 10 26 kg. What is the radius of the new
moon’s orbit? What is the orbital period? Assume
that the orbit is circular. (G = 6.673 × 10 −11
N•m 2 /kg 2 )
14. A satellite orbits Jupiter 6.40 × 10 3 km above its
surface. Given that the mass of Jupiter is
1.90 × 10 27 kg and the radius of Jupiter is
7.15 × 10 7 m, calculate the period of orbit of the
satellite.
15. Somewhere between planet X and its moon there
exists a point where the planet pulls on a mass one
way, the moon pulls the other with an equal force,
so that the net gravitational force at this point is
zero. Locate this point if the mass of the planet is
1.95×1025kg, the mass of the Moon is 7.85×1023kg,
and the distance between the centers of the two is
3.45×108m.
7. The distance between Pluto and the Sun is 39.1
times more than the distance between the Sun and
Earth. Calculate the time taken by Pluto to orbit the
Sun in Earth days.
8. Venus orbits the Sun with an orbital radius of
1.08 × 10 11 m. Given that the mass of the Sun is
2.0 × 1030 kg, calculate the period of Venus’s orbit.
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