Laser break detection for high speed passing

So, I'm working on this project where a laser and a photoresistor are connected to an Arduino. The goal is when a 2inch board swings through, it breaks the laser beam, which triggers an LED to light up. The challenge is that the board is going to be traveling at 30-50mph.

Is a photoresistor able to detect the break in that quick of a moment? Does anyone have a better idea on what to use that will work better in detecting the 2inch board passing through?


60 miles/hour x 5280 feet/mile x 12 inch/foot x 1 hr/60 minutes x 1 minute/60 seconds
= 1056 inches/second
So in 1 second, it will move 1056 inches
In 1 millisecond, it will move 1.056 inches
In 2 mS, it will move 2.112 inches.
2mS seems like plenty of time to trigger a photosensor.
Got any specs on yours?

Not exactly. When I move an object passed the laser and photoresistor, it isn't detecting the break. I'm not sure why? I assumed that the photoresistor is not able to detect it quick enough?

Depends on the pullup resistor and wire capacitance (if any) and the software.
Post a diagram of how you have hooked it up.
And your code (inside code tags).

Even modulated IR (~38khz) and a common 3-pin IR receiver has a reaction time of 1msec.
And a beam thickness of ~5mm.
Why a laser.