Answer:
The observer sees the space-probe 9.055m long.
Explanation:
Let 
be the length of the space-probe when measured at rest, and 
be its length as observed by an observer moving at velocity 
, then
Now, we know that 
and 
, and putting these into 
we get:
Thus, an observer moving at 0.95c observes the space-probe to be 9.055m long.
Angular acceleration = (change in angular speed) / (time for the change)
change in angular speed = (zero - 2,600 RPM) = -2,600 RPM
time for the change = 10 sec
Angular acceleration = -2600 RPM / 10 sec = -260 rev / min-sec
(-260 rev/min-sec) x (1 min / 60 sec) = <em>-(4 1/3) rev / sec²</em>
Since the acceleration is negative, the motor is slowing down.
You might call that a 'deceleration' of (4 1/3) rev/sec² .
The average speed is 1/2(2,600 + 0) = 1,300 rev/min = (21 2/3) rev/sec.
Number of revs = (average speed) x (time) = (21 2/3) x (10sec) = <em>(216 2/3) revs</em>
Answer:
the earth orbits a star called the sun
The sound was repeated because of the phenomenon of echo. The speed of sound in the metal is 800 m/s.
Echo results from the reflection of sound waves. The reason why a sound may be heard twice owes to the phenomenon of reflection which leads to echo.
To determine the speed of sound in the metal;
Length of metal = 1000 m
Time taken between the two sounds = 2.5 s
Using the formula;
V = 2d/t
V = 2(1000)/2.5
V = 800 m/s
A Belgian Astronomer and Cosmotologist who formulated the modern Big Bang theory, which states that the universe began in a cataclysmic explosion of a small, primeval “super-atom”
