Download Assignment 2 - Faculty of Geoinformation and Real Estate

DEPARTMENT OF GEOINFORMATION
FACULTY OF GEOINFORMATION & REAL ESTATE
UTM JOHOR BAHRU
SEMESTER II SESSION 2014/2015
MGHS1524 Satellite System & Earth Observation
Assignment 2: Understanding Satellite Orbit
1. Match the physical laws on the left with the best term or description on the left
a) Kepler’s 1st Law
(i) Equal areas in equal times
b) Kepler’s 2nd Law
(ii) Planetary orbits are ellipses
rd
c) Kepler’s 3 Law
(iii)Relates orbital period to orbit size
2. At what location does an artificial Earth satellite in elliptical orbit have its greatest
speed?
a. nearest the Earth
b. farthest from the Earth
c. between Earth and Moon
d. between Earth and Sun
3. Which of the following best describes the property of the period of orbital revolution
for an Earth satellite?
a. greater when the orbital radius is smaller
b. greater when the orbital radius is larger
c. independent of the orbital radius
d. determined mainly by the satellite's mass
4. Of the nine known planets in our solar system, the innermost is Mercury. When
compared to the other planets in the system, Mercury has the:
a. greatest centripetal acceleration.
b. greatest period of revolution.
c. smallest angular velocity.
d. smallest tangential velocity.
5. According to Kepler's second law, Halley's Comet circles the Sun in an elliptical path
with the Sun at one focus of the ellipse. What is at the other focus of the ellipse?
a. nothing
b. the Earth
c. The comet itself passes through the other focus.
d. The tail of the comet stays at the other ellipse.
6. Find the net force for each of these situations
ANS: 0 N
ANS: 5 N, left
ANS: 0 N
ANS: 15 N, up
7. Ethan is dragging a bag of grass from the garage to the street on the evening before
garbage pick-up day. The diagram at the right is a free-body diagram. It uses arrows
to represent the forces acting upon the bag. Each force is labeled according to type.
The magnitude of the force is represented by the size of the arrow. Use the free body
diagram to determine the net force acting upon the bag. The values of the individual
forces are:
Fgrav = Fnorm = 60.5 N
Fapp = 40.2 N
Ffrict = 5.7 N.
ANS: 34.5 N, right
8. What acceleration will result when a 10 N net force applied to a 4-kg object? A 8-kg
object?
F = 10 N; For 4 kg:
∴ a = F/m
= 10/4
= 2.5 ms-2
For 8 kg:
∴ a = F/m
= 10/8
= 1.25 ms-2
9. A net force of 20 N causes a mass to accelerate at a rate of 6 m/s2. Determine the
mass.
F = 20 N, a = 6 ms-2
∴ m = F/a
= 20/6
= 3.333 kg
10. An object is accelerating at 4 m/s2. If the net force is tripled and the mass is doubled,
then what is the new acceleration?
a = 4 ms-2,
Fnew = 3Fold
Æ a= F/m;
mnew = 2mold
∴ anew = 3(4 ms-2)/2
= 6 ms-2
11. An
A object is accelerating
a
at 4 m/s2. Iff the net forcce is tripled and
a the masss is halved,
thhen what is the
t new acceeleration?
a = 4 ms-2,
Fnew = 3Fold
Æ a= F//m;
mnew = 0.5mold
∴ anew = 3(4 ms-2)//0.5
= 24 ms-2
12. Problem
P
#1
Deterrmine the forrce of gravittational attraaction betweeen the earth (m=5.98 x 10
1 24 kg) and a
75 kgg physics stu
udent if the student
s
standding at sea leevel, a distannce of 6.37 x 106 m from
m
earth’s center.
Fgraav =
(6.67 × 10
1 −11 Nm
2
kg 2
) ⋅ (5.98 × 10 24 kg
k ) ⋅ (75kg )
(6.37 ×106 m) 2
= 737.241 N
13. Problem
P
#2
Deterrmine the forrce of gravittational attraaction betweeen the earth (m=5.98 x 10
1 24 kg) and a
75 kgg physics stu
udent if the student
s
if thee student is inn an airplanee at 40000 feeet above
earth’s surface. This
T would place
p
the studdent a distannce of 6.38 x 106 m from
m earth’s
centeer.
2
(6.67 ×10
0 −11 Nm kg 2 ) ⋅ (5.98 × 10 24 kg
g ) ⋅ (75kg )
Fgrav =
6
2
(6.38 × 10 m)
= 734.932 N