Astudent is concluding an expirinent to determine how far a ball will roll down a ramp based on the angel of incline. what are three possible controls for this expiriment

“other instruments such as gravimeters and magnetometers are also used in the search for petroleum. extracting crude oil normally starts with drilling wells into an underground reservoir. when an oil well has been tapped, a geologist (known on the rig as the "mudlogger") will note its presence. “ this is what i found on google i hope it

I’m good with pshycology