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catalyst55
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A spacecraft (Lo = 80 m) travels past a space
station at speed 0.7c. Its radio receiver is on
the tip of its nose. The space station sends a
radio signal the instant the tail of the spacecraft
passes the space station.
(a) What is the length of the spacecraft in the
reference frame of the space station?
L=80(1-.7^2)^.5 = 57m (fine)
(b) What is the time taken for the radio signal
to reach the nose of the spacecraft ,
according to those on the space station?
t= s/v = 57/c = 1.9x10^-7 s (They get 6.3x10^-7 s (consequential 'errors' result) which can be obtained by t= 57 / 0.3c - but this logic seems to contradict einstein's 2nd postulate since the signal must move relative to the spacecraft at c)
(c) How far from the space station is the nose
of the spacecraft when it receives the radio
signal from the reference frame of the
space station?
S(t) = s(moved) + s(length of ship)
s= 0.7c *(1.9x10^-7) + 57 = 97m
their answer: 190m
(d) What is the time taken for the radio signal
to reach the nose, according to those on
the spacecraft ?
t = s / v = 97 / c = 3.2x10^-7s
their answer: 2.67x10^-7s
What am i doing wrong?
Thanks.
station at speed 0.7c. Its radio receiver is on
the tip of its nose. The space station sends a
radio signal the instant the tail of the spacecraft
passes the space station.
(a) What is the length of the spacecraft in the
reference frame of the space station?
L=80(1-.7^2)^.5 = 57m (fine)
(b) What is the time taken for the radio signal
to reach the nose of the spacecraft ,
according to those on the space station?
t= s/v = 57/c = 1.9x10^-7 s (They get 6.3x10^-7 s (consequential 'errors' result) which can be obtained by t= 57 / 0.3c - but this logic seems to contradict einstein's 2nd postulate since the signal must move relative to the spacecraft at c)
(c) How far from the space station is the nose
of the spacecraft when it receives the radio
signal from the reference frame of the
space station?
S(t) = s(moved) + s(length of ship)
s= 0.7c *(1.9x10^-7) + 57 = 97m
their answer: 190m
(d) What is the time taken for the radio signal
to reach the nose, according to those on
the spacecraft ?
t = s / v = 97 / c = 3.2x10^-7s
their answer: 2.67x10^-7s
What am i doing wrong?
Thanks.
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