Context. Matter leaving the donor during mass transfer spinsup the gainer and creates a hot spot in the impact area. If the kineticenergy of the enhanced rotation combined with the radiative energy ofthe hot spot exceeds the binding energy of the system, matter canescape from the binary. Aims. We calculate the amount of mass lost during eras of fastmass transfer. We simulate the distribution of mass ratios and orbitalperiods for interacting binaries with a B-type primary at birth wheremass transfer starts during hydrogen core burning of the donor. Methods. We used the initial distributions of primary mass, massratio and orbital period established in a previous paper. The amount oftime the binary shows Algol characteristics within different values ofmass ratio and orbital period was fixed from conservative and liberalevolutionary calculations. We use these data to simulate thedistribution of mass ratios and orbital periods of Algols with theconservative as well as the liberal model. Results. Rapid rotation and hot spots are frequently observed atthe surface of the gainer in a semi-detached binary. The mass transferrate for low-mass binaries is never sufficiently large to achieve massloss from the system. Intermediate-mass binaries blow away a largefraction of the transferred mass during short eras of rapid masstransfer. Conclusions. We compare mass ratios and orbital periods ofAlgols obtained by conservative evolution with those obtained by ourliberal model. We calculate the amount of matter lost according to ourmodel by binaries with an early B-type primary at birth. Since binarieswith a late B-type primary evolve almost conservatively, the overalldistribution of mass ratios will only yield a few Algols more with highmass ratios than conservative calculations do. Whereas the simulateddistribution of orbital periods of Algols fits the observations well,the simulated distribution of mass ratios produces always too fewsystems with high values. Key words: binaries: eclipsing - stars: evolution - stars: mass-loss - stars: statistics
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