Let (Bt)t≥0 be standard Brownian motion starting at y, Xt = x + ∫t0V(Bs) ds for x ∈ (a, b), with V(y) = yγ if y≥0, V(y)=−K(−y)γ if y≤0, where γ>0 and K is a given positive constant. Set τab=inf{t>0: Xt∉(a, b)} and σ0=inf{t>0: Bt=0}. In this paper we give several informations about the random variable τab. We namely evaluate the moments of the random variables \(B_{\tau _{ab} } and B_{\tau _{ab} \wedge \sigma _0 } \), and also show how to calculate the expectations \({\mathbb{E}}\left( {\tau _{ab}^m B_{\tau _{ab} }^n } \right) and {\mathbb{E}}\left( {\left( {\tau _{ab} \wedge \sigma _0 } \right)^m B_{\tau _{ab} \wedge \sigma _0 }^n } \right)\). Then, we explicitly determine the probability laws of the random variables \(B_{{\tau }_{ab} } and B_{{\tau }_{ab} \wedge \sigma _0 }\) as well as the probability \({\mathbb{P}}\left\{ {X_{\tau _{ab} } = a\left( {or b} \right)} \right\}\) by means of special functions.