40.64 cm is the answer to your question.
C.) Laser. the light from the laser reflects off the shiny surface as the CD rotates
![Power=\frac{Work}{Time}=\frac{Force\times distance}{time}](https://tex.z-dn.net/?f=Power%3D%5Cfrac%7BWork%7D%7BTime%7D%3D%5Cfrac%7BForce%5Ctimes%20distance%7D%7Btime%7D)
If he wants to increase power, force must increase and decrease time.
1. circle graph
2. Bar graph
3. line graph
hope this helps