Phys 3250 Topics in Relativity
Exam 1 Solution
1. A man at the back of a 50-m long rocket traveling at 0.6c with respect to a nearby
planet observes a flash go off at the front of the rocket 7.0x10-7 s after passing
another man standing on the nearby plan
Phys 3250 Topics in Relativity
Homework Set 10: Handout Problems # 1, 3 & 7
1. Black Hole Alpha has mass M = 5 km and a horizon at r = 2M = 10 km. A stone
starting from rest far away falls radially into Black Hole Alpha.
A. At what velocity does a shell o
Phys 3250 Topics in Relativity
Homework Set 10: Handout Problems # 1, 2 & 3
1. A black hole has mass M = 5 kilometers, a little more than three times that of the
Sun. Two concentric shells surround this black hole. The inner shell has rcoordinate (reduced
Topics in Relativity
Homework Set 7
Chapter 8 # 8.31, 8.32, 8.34, 8.36, 8.39 & 8.40
8.31. Calculate the energy of a proton whose velocity is 0.8c.
From the appendix, the rest mass energy of a proton is m0 = 938.3 MeV
1
K = mc 2 m0 c 2 = m0 c 2
1=
2
1
Phys 3250 Topics in Relativity
Homework Set 9: Handout Problems # 1, 2, 3, 4 & 5
1. Two firecrackers explode at the same place in a laboratory and are separated by
a time of three years as measured by a laboratory clock.
A. What is the spatial distance be
Topics in Relativity
Homework Set 1
1.11, 1.13, 1.17, 1.18, 1.19 & 1.20
1.11 A man (O) in the back of a 20-ft flatcar moving at 30 ft/s records that a flashbulb is
fired in the front of the flatcar two seconds after he has passed a man (O) on the ground.
Topics in Relativity
Homework Set 3
3.9, 3.10, 3.11 & 3.12
3.9. As determined by O, a lightning bolt strikes at x = 60m, y = z = 0, t = 8x10-8 s. O
has a velocity of 0.6c along the x-axis of O. What are the space-time coordinates of the
strike as determin
Topics in Relativity
Homework Set 2
2.8, 2.9, 2.10 & 2.11
2.8. Repeat problem 2.3 for the case where the picture is taken when the right end of
the rod passes the camera.
s
s
0.9m
L
In the illustration above the upper bar shows the apparent position of th
Phys 3250 Topics in Relativity
Exam 2 Solution
1. The pilot of rocket A moving east at 0.8c (as measured by an observer on Earth)
sees rocket B moving towards him at 0.9c (as measured by the pilot on rocket A).
What is the speed of rocket B as measured by
Topics in Relativity
Homework Set 4
Chapter 4 # 4.6, 4.8, 4.9 & 4.10
Chapter 5# 5.7, 5.8, 5.10 & 5.11
4.6. An airplane is moving with respect to the Earth with a speed of 600 m/s. Its proper
length is 50 m. By how much will it appear to be shortened to an
Announcements
Homework Set 1 is due now. I will accept
the homework if placed in my mailbox by
5:00pm today
Solution to HW set 1 will be posted
tomorrow morning on the class website and
in the class D2L shell.
Homework Set 2: Schaums Outline # 2.8,
2.9, 2
Topics in Relativity
Homework Set 6
Chapter 7 # 7.17, 7.18, 7.19, 7.24 & 7.25
Plus derivation of ux uy and uz
7.17. The pilot of a rocket moving at a velocity of 0.8c relative to the Earth observes a
second rocket approaching in the opposite direction at
Topics in Relativity
Homework Set 5
Chapter 6 # 6.24, 6.28, 6.31, 6.34, 6.35 & 6.37
6.24. An unstable particle with a mean lifetime of 4 s is formed by a high-energy
accelerator and projected through a laboratory with a speed of 0.6c. (a) What is the
mean
Topics in Relativity
Homework Set 8
Chapter 8 # 8.41, 8.42, 8.44, 8.45 & 8.46
8.41. Suppose that electrons in a uniform magnetic field of flux density 0.03T move in a
circle of radius 0.2m. What are the velocity and kinetic energy of the electrons?
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