A new model for determining flyrock drag coefficient

•Flyrock is probably the most dangerous adverse effect of blasting due to its potential to cause injuries to personnel.•Proper selection of drag coefficient improves precision flyrock throw determination and safe distance definition.•High-speed cameras were used to film flyrock events.•Terminal velocity concept was developed and used as method for drag coefficient determination.•The acquired results prove the concept but indicate that the concept can be further developed and improved.