# Math Help - Hand of a Clock

1. ## Hand of a Clock

Through how many radians does the minute hand of a clock turn in 24 minutes?
(1) 0.2π (3) 0.67π
(2) 0.4π (4) 0.8π

MY WORK:

24 minutes/60 minutes = 2/5 = 0.4pi or so I thought.

How can this be?

2. Originally Posted by magentarita
Through how many radians does the minute hand of a clock turn in 24 minutes?
(1) 0.2π (3) 0.67π
(2) 0.4π (4) 0.8π

MY WORK:

24 minutes/60 minutes = 2/5 = 0.4pi or so I thought.

How can this be?

You're on the right track. What you did with the 24 min/ 60 min = 2/5 is good...but we have 2/5 of what? The whole circle. A circle has how many degrees [or radians, in this case] in it? Multiply 2/5 to that and see what you get.

--Chris

3. ## Do you???

Originally Posted by Chris L T521
You're on the right track. What you did with the 24 min/ 60 min = 2/5 is good...but we have 2/5 of what? The whole circle. A circle has how many degrees [or radians, in this case] in it? Multiply 2/5 to that and see what you get.

--Chris
Do you mean multiply 2/5 times 360 degress or 2pi?

I multiplied 2/5 by 360 degress and got 144.

What did I do wrong?

4. Originally Posted by magentarita
Do you mean multiply 2/5 times 360 degress or 2pi?

I multiplied 2/5 by 360 degress and got 144.

What did I do wrong?
In this case, you would multiply by $2\pi$, since we are dealing with choices of angles in radians.

--Chris