4-62.
An astronaut in training is spinning around in a device that rotates at
30 revolutions per minute. (a) If the astronaut is 7.5 m from the
centre
of the device, what is the magnitude of the centripetal acceleration?
(b)
Express the answer in terms of "g," the magnitude of the acceleration
due
to gravity. [Ans. (a) 74 m/s2 (b) 7.6 g]
ACCUMULATED
SOLUTION
The
expression for centripetal acceleration is: ac = 4p2r/T2
Correct!ac
= 4p2r/T2 Text
Eq. 4-16.
In
fact, the other choice ac = v2/r
is also correct. We will use ac = 4p2r/T2
but at the end you should go back and follow the alternate solution as
well.
For
this solution we need the value of T which is:
(A) the
time for one revolution
(B) the
time for 30 revolutions
(C) the
number of revolutions in one second