Relationship between the initial velocity v₀ and the initial deceleration a₃₀₀ as obtained by the procedure described in Sect. 4 for α = 1 (dashed line) and α = 2 (full line). The pairs of values (a₃₀₀, v₀) derived from the sample of seven EUV waves (see Table 2) are inserted as bold dots. The cross denotes the pair (a₃₀₀, v₀) obtained for the representative EUV wave described in Sect. 2 (see Fig. 1).