Explain the cavendish experiments for the …

Gravitational Constant: Cavendish experiment

• Cavendish performed an experiment to calculate the value of G.
• To calculate the value of G he took a wooden plank and attached two 2 balls on either side of the plank and hung this with a thin thread from the top.
• He introduced 2 very big balls and those balls are near the smaller balls.
• He observed that the small balls got attracted to big balls and wooden plank started rotating and as a result the thin thread started twisting.
• This happened because of force of attraction between the small balls and bigger balls.
• He observed that :-

1. Plank rotates till twisting force becomes equal to the gravitational force between the balls.

? = G m₁m₂/r²

LƟ = G m₁m₂/r²

• By using the above equation he calculated the value of G,

• G= 6.67x10^-11Nm²/kg²                        
• Units of G : Nm²/kg²