### P2_3 Tennis Ball Tunnelling

#### Abstract

This paper aims to calculate the probability of a tennis ball quantum tunnelling through a tennis racket. This is done by treating the tennis ball as a single particle, and making the potential barrier equal to the energy required to break the strings classically. The probability of tunnelling through a racket is found to be 3.6exp(-2.9x10^31). This very low probability matched with what would be expected. The paper also briefly discusses the problem of decoherence when applying quantum mechanics to macroscopic systems.