Time measurement

[[email protected]]

could anyone suggest how tor measure the vehicle run time. I mean to measure the time vehicle takes from 0.5m line to 8.5m line.

The rules manual suggest to use the photogate system. We need to host a invitational event and we don't have photogate system.
How the manual measurement works. It maybe very challenging if someone to start a timer (stop clock) at 0.5m line and runs to 8.5m line before the vehicle crosses to stop the timer. Could anyone suggest. Thanks

[SPP SciO]

You can set up a laser pointer that points across the track. As the dowel breaks it, the timers should see a little flash on the dowel. If you have 3 separate timers and use the middle time, it would be consistently fair (if not the most accurate).

Photogate timers are more common than you think though; if you ask a physics teacher, you may be able to find a set to borrow.

[[email protected]]

Thank you for the suggestion. I understand that laser pointer to be installed at both 0.5m line and 8.5m line across the track. But I couldn't understand how to start and stop the timer when dowel breaks the laser beam in both points.

Also I couldn't understand below sentence
"the timers should see a little flash on the dowel".

Could you please confirm what kind of timer you refer to?
If any link to (like Amazon/ebay) would be great help.

[SPP SciO]

Thank you for the suggestion. I understand that laser pointer to be installed at both 0.5m line and 8.5m line across the track. But I couldn't understand how to start and stop the timer when dowel breaks the laser beam in both points.

Also I couldn't understand below sentence
"the timers should see a little flash on the dowel".

Could you please confirm what kind of timer you refer to?
If any link to (like Amazon/ebay) would be great help.

https://www.vernier.com/products/sensors/vpg-btd/ This is the "standard" photogate you'll see in a lot of places.

If you don't have a photogate though, but you have two laser pens, you mount the laser pens to shine across the track. As the wooden dowel breaks the beam, you'll see the little red or green spot on the dowel. It's a visual cue that tells you "start the timer." Of course by the time you click the watch, the vehicle is past the line, but hopefully the reaction time error cancels out when you stop the timer at the second laser.

[[email protected]]

Thank you. We are checking with school for photo gate availability. In worst case we may go with manual method using timer/stop watch and laser pens.

If I understand correctly, the person taking measurement needs to run fast enough to the 8.5m line after starting the timer at 0.5m line.
Does that correct understanding ?

[SPP SciO]

Thank you. We are checking with school for photo gate availability. In worst case we may go with manual method using timer/stop watch and laser pens.

If I understand correctly, the person taking measurement needs to run fast enough to the 8.5m line after starting the timer at 0.5m line.
Does that correct understanding ?

Full disclosure, I've never done this, so I don't know. But I don't think you'll need any running. You could just stand in a position where you can clearly see both lines. The whole idea of the laser/dowel is so you have an unambiguous indicator of when the vehicle hits the threshold, that's not dependent on the angle you're viewing from and your distorted perception.