steven7mwesigwa
steven7mwesigwa

Reputation: 6730

what is the hour hand rotation angle per second on a wall clock?

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

Answers (2)

duffymo
duffymo

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

Thomas Jager
Thomas Jager

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

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