This device allows the study of free fall over a height of 145 cm.
An electromagnet powered with 6 V placed at the top of the rail makes it possible to retain a metal ball. When the power is cut, the ball falls.
Two photogates connected to a digital stopwatch record the passage of the ball.

Composition:

• 1 rail graduated from 0 to 145 cm, section 20 x 20 mm (delivered in 4 tubes to assemble)
  
• 1 base with 2 screws to adjust the verticality
  
• 1 6 V electromagnet with safety banana sockets (to be completed with a 6 V DC power supply ref. AL12V)
  
• 1 plumb line for vertical adjustment
  
• 1 steel ball
  
• 1 plastic receptacle with anti-rebound device for the ball
  
• 2 photogates
  
• 1digital counter