Reputation: 6730
Am writing a javascript function to rotate the hour hand per second .
For example:
1 second = 6 deg ("rotation angle")
1 minute = 6 / 60 = 0.1 deg ("rotation angle per second")
Question
1 hour = ???? = ???? deg ("rotation angle per second")
My Initial guess
my guess was : since 1 hour = 3600 seconds
then 1 hour = 6 / 3600 = 0.001666667 deg ("rotation angle per second")
But this was wrong when i implemented it in my clock application.
It made the hour hand move only by 1 / 5 hours per hour instead of 1
Upvotes: 3
Views: 2738
Reputation: 308968
The hour hand rotates 360 degrees
in twelve hours; its angular velocity is 360 degrees/12 hours = 30 degrees/hour
.
There are 3600 seconds
in an hour.
Therefore, the angular velocity of the hour hand is
(30 degrees/hour)*(1 hour/3600 seconds) = 0.0083333333 degree/second
It's a simple matter of units.
Upvotes: 1
Reputation: 5265
12 hours : 360 degs
1 hour : 30 degs
60 mins : 30 degs
1 min : 0.5 degs
60 s : 0.5 degs
1 s : 0.00833333333... degs
If my math is right, that's your answer
Upvotes: 4