AQA GCSE Kerboodle Book: P14.3 Light Design an experiment using a light meter and a rectangular glass block to find out how the absorption of light by a glass block depends on the thickness of the block. (6 marks)

Dis the

The answer is 4f======since electrostatic force is given by    we let f be the electrostatic force when  r = 1 m    if we let  denote the electrostatic force when the distance is decreased so that r = 0.5m, then    we established earlier that f = kq₁q₂. therefore    the force will now be 4f.