FOR MORE EXAMS
EMAIL:
Physics 140 - University of Michigan,
Department of Physics Studio 20/21:
More Gravity Questions and answers
Studio 20/21: More Gravity
Physics 140 - University of Michigan, Department of Physics
Name:
Problem 1
Comet Halley moves in an elongated elliptical orbit around the sun. Its
distances from the sun at perihelion and aphelion are 8.75 × 107 km and
5.26×109 km, respectively. Calculate the orbital semi-major axis (a),
eccentricity (e), and period (T). HINT: See figure on elliptical orbits from
notes
FOR MORE EXAMS
EMAIL:
, FOR MORE EXAMS
EMAIL:
7
× × 109 km
Solution: a = 8. 75 10 km +52
. 26
=2 . 67 × 109 km
× 7 km
e =1 − 8. 75 10a =0 . 967
3/ 2
2πa
T = √ GM sun =75 . 5 years
Problem 2
The most efficient way to send a spacecraft from the earth to another
planet is by using Hohmann transfer orbit. If the orbits of the departure
and destination are circular, the Hohmann transfer orbit is an elliptical
orbit whose perihelion and aphelion are tangent to the orbits of the two
planets. The rockets are fired briefly at the departure planet to put the
spacecraft into the transfer orbit; the spacecraft then coasts until it
reaches the destination planet. The rockets are then fired again to put
the spacecraft into the same orbit about the sun as the desination
Solution:
GMm mv 2
=
r2 r
GM
v2 =
r
r GM
v =
r
r GM r GM
ve = andv m =
re rm
FOR MORE EXAMS
EMAIL:
EMAIL:
Physics 140 - University of Michigan,
Department of Physics Studio 20/21:
More Gravity Questions and answers
Studio 20/21: More Gravity
Physics 140 - University of Michigan, Department of Physics
Name:
Problem 1
Comet Halley moves in an elongated elliptical orbit around the sun. Its
distances from the sun at perihelion and aphelion are 8.75 × 107 km and
5.26×109 km, respectively. Calculate the orbital semi-major axis (a),
eccentricity (e), and period (T). HINT: See figure on elliptical orbits from
notes
FOR MORE EXAMS
EMAIL:
, FOR MORE EXAMS
EMAIL:
7
× × 109 km
Solution: a = 8. 75 10 km +52
. 26
=2 . 67 × 109 km
× 7 km
e =1 − 8. 75 10a =0 . 967
3/ 2
2πa
T = √ GM sun =75 . 5 years
Problem 2
The most efficient way to send a spacecraft from the earth to another
planet is by using Hohmann transfer orbit. If the orbits of the departure
and destination are circular, the Hohmann transfer orbit is an elliptical
orbit whose perihelion and aphelion are tangent to the orbits of the two
planets. The rockets are fired briefly at the departure planet to put the
spacecraft into the transfer orbit; the spacecraft then coasts until it
reaches the destination planet. The rockets are then fired again to put
the spacecraft into the same orbit about the sun as the desination
Solution:
GMm mv 2
=
r2 r
GM
v2 =
r
r GM
v =
r
r GM r GM
ve = andv m =
re rm
FOR MORE EXAMS
EMAIL:
