Respuesta :
It would rotate 360 degrees because 18 seconds is twice the amount of 9 seconds, so you need to multiply 180 by 2, which is 360, or one full rotation.
since 9*2=18 all you have to do is the same to 180...
180*2=360
Answer: The marble rotates 360 degrees in 18 seconds
180*2=360
Answer: The marble rotates 360 degrees in 18 seconds