It is noon. All three hands of your watch are in the 12 o\'clock position. After
ID: 2255732 • Letter: I
Question
It is noon. All three hands of your watch are in the 12 o'clock position. After how many seconds will the second hand for the first time be again in the same position as the minute hand?
(Note that unlike with the previous "catching up" problems for linear motion, the total "distance" moved in radians will never be the same. What is the requirement for the difference in angular displacements, such that they end up in the same position on the dial of the watch?)
This is my work so far:
2pi/60 * (t-60) = 2pi/3600 + t
I know I need to solve for t but I cannot figure out the algebraic steps involved to get t=61 from this. Please help and please show your work in detail so I can better understand. Thank you
Explanation / Answer
angle coverd by seconds hand in 1s = 360/60 = 6 degrees
angle covered by minutes hand in 1s = 360/(60*60) = 1/10 degrees
let they both meet after t secs
by this time, seconds hand has made 1 complete revolutions.
so difference between the angles covered after t secxs= 360
so
6t - t/10 = 360
60t - t = 3600
t = 3600/59
t = 61.017 s
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