Student:
Ms. Elbein
AP Physics
Due Date:
CW3.6 Gravity using Apollo 11
Fields and field lines
(resourcefulphysics.org)
Gravitational field strength, g.
Data required:
G = 6.67  10-11 N m2 kg-2
radius of the Earth = 6.4  106 m
mass of the Earth = 6.0  1024 kg
1)
kg-1.
Treating the Earth as a perfect sphere, show that the field strength at the Earth’s surface is around 9.8 N
2)
What is the strength of the gravitational field due to you at a distance equal to the radius of the Earth?
3)
In view of your answers to the two questions above, your field strength at a distance of 6400 km from
you (where the Earth’s centre is) is MUCH weaker than the Earth’s field strength at a distance of 6400 km from
its centre (where you are right now). Can you explain why is then that you and the Earth exert the same size of
force on each other?
Assignment taken from: http://tap.iop.org/fields/gravity/402/page_46820.html
Student:
Ms. Elbein
AP Physics
Due Date:
CW3.6 Gravity using Apollo 11
Distance r
from centre
of Earth /
106 m
Ground elapsed time /
hours:minutes:seconds
Events
launch from surface of Earth
ignition to inject into coasting
orbit to Moon (5 m 20 s burn)
coasting begins with no rocket
burn
Velocity v / m s–1
00:00:00
02:44
03:08:00
1
11.054
8406
10 minute =
600 s interval
03:58:00
04:08:00
2
2A
26.306
29.030
5374
5102
10 minute =
600 s interval
05:58:00
06:08:00
3
3A
54.356
56.368
3633
3560
10 minute =
600 s interval
09:58:00
10:08:00
4
4A
95.743
97.242
2619
2594
10 minute =
600 s interval
19:58:00
20:08:00
5
5A
169.900
170.945
1796
1788
26:44:57.92
26:45:01.47
6
7
209.228
209.232
1531.56
1527.16
32:58.00
33:08:00
8
8A
240.624
241.417
1356
1352
no rocket burn until this time
3.55 second burn
10 minute =
600 s interval
Landing on Moon. Moon walk.
Rocket burn to return
Coasting back to Earth
10 minute =
600 s interval
166:38:00
166:48:00
9
9A
241.637
240.740
1521
1524
10 minute =
600 s interval
172:18:00
172:28:00
10
10A
209.722
208.737
1676
1681
10 minute =
600 s interval
178:28:00
178:38:00
11
11A
170.891
169.766
1915
1923
10 minute =
600 s interval
187:58:00
188:08:00
12
12A
96.801
95.241
2690
2715
10 minute =
600 s interval
191:48:00
191:58:00
13
13A
56.368
54.310
3626
3699
10 minute =
600 s interval
193:48:00
193:58:00
14
14A
28.427
25.640
5201
5486
10 minute =
600 s interval
Rocket burn on re-entry
194:38:00
194:48:00
195:03
15
15A
13.311
10.036
7673
8854
150:28
Assignment taken from: http://tap.iop.org/fields/gravity/402/page_46820.html
Student:
Ms. Elbein
AP Physics
Due Date:
CW3.6 Gravity using Apollo 11
For each pair of data on the previous page:
1) Calculate the average distance from the center of Earth. Write the general equation here:
2) Use the two velocities provided to calculate the acceleration of Apollo 11. The time interval is given. Write
the general equation here:
3) Organize that data into a table below.
4) Use a computer to graph mean distance from earth vs acceleration. How will you know if your graph is
correct?
Assignment taken from: http://tap.iop.org/fields/gravity/402/page_46820.html