Yes, a Vernier photogate and Vernier Time of Flight Pad can be used together to measure the acceleration due to gravity.
You will calculate the acceleration due to gravity using the standard kinematics equation h = 1/2gt^2,
where h is the height, g is the acceleration due to gravity, and t is the fall time (measured using the photogate and Time of Flight Pad).
When using a Vernier (BTD) Photogate you will need the following:
Photogate (VPG-BTD)
Time of Flight Pad (TOF-VPL)
One of the following LabQuest interfaces:
LabQuest 3 (LABQ3) – use with LabQuest App, Logger Pro 3, Graphical Analysis App, or Graphical Analysis Pro
LabQuest Stream (LQ-STREAM) – use with Logger Pro 3, Graphical Analysis App, or Graphical Analysis Pro
LabQuest Mini (LQ-MINI) – use with Logger Pro 3, Graphical Analysis App, or Graphical Analysis Pro
LabQuest 2 (LABQ2) – use with LabQuest App, Logger Pro 3, Graphical Analysis App, or Graphical Analysis Pro
LabQuest (LABQ) – use with LabQuest App, Logger Pro 3, Graphical Analysis App, or Graphical Analysis Pro
LabPro – use with Logger Pro 3
1. First, connect the Photogate to DIG 1 on the interface. Then, connect the Time of Flight Pad to DIG 2 on the interface.
Connecting in the above order ensures appropriate time measurement.
2. Align the Time of Flight Pad so the object will pass through the gate and land on the center of the pad.
Measure the distance between the center of the photogate and the top of the time of flight pad.
3. Connect the interface to your data collection device (computer, Chromebook, or mobile device)
4. Launch the data collection software.
5. Set up the data collection mode.
Logger Pro 3: Open the file “Pulse Timing – Two Gates.cmbl”
The file is in the following folder – Experiments > Probes & Sensors > Photogates.
LabQuest App: Set the photogate timing mode to Pulse Timing
The distance value does not matter for this experiment.
Graphical Analysis and Graphical Analysis Pro: Set the Photogate Mode Measurement to Timer or Period
Select the option for Time between Gates.
6. Start data collection.
7. Drop an object through the Photogate and onto the Time of Flight Pad.
The kinematics equation assumes that the falling object was dropped from rest.
When dropping it, hold it just above the beam of the Photogate.
Be careful not to accidentally break the Photogate beam before you are ready to drop it!
8. The Photogate starts the timer and the Time of Flight Pad stops it reporting the Pulse Time (fall time).
Use the height measured in step 2 and the fall time with the kinematics formula to calculate g.
When using the Go Direct Photogate you will need the following:
Go Direct® Photogate (GDX-VPG)
Time of Flight Pad (TOF-VPL)
Go Direct® Time of Flight Pad Cable (TOF-CB-GDX)
1. Connect the Go Direct Photogate to the Time of Flight Pad using the Time of Flight Pad cable.
2. Align the Time of Flight Pad so the object will pass through the gate and land on the center of the pad.
Measure the distance between the center of Gate 1 on the Go Direct Photogate and the top of the time of flight pad.
3. Launch the data collection software. (Logger Pro 3 cannot be used with this sensor.)
4. Connect to the Go Direct Photogate via USB or wireless Bluetooth connection.
For specific instructions for your platform, see https://www.vernier.com/start/gdx-vpg
5. Set up the sensor channel to Gate 1/Remote Gate – Timing.
6. Start data collection.
7. Drop an object through the Photogate and onto the Time of Flight Pad.
The kinematics equation assumes that the falling object was dropped from rest.
When dropping it, hold it just above the beam of Gate 1 of the Go Direct Photogate.
Be careful not to accidentally break the photogate beam before you are ready to drop it!
8. The photogate starts the timer and the Time of Flight Pad stops it reporting the Pulse Time (fall time).
Use the height measured in step 2 and the fall time with the kinematics formula to calculate g.