Angry Bear

Yes, there are three bears! Very good! Two of them are cubs and one is a very large female. At the same time that you found them, you also hear the poachers off in the distance say, "The bastard must have gone in here. Let's get him!" This gives you an idea.

You wave some honeycomb under the nose of one of the cubs. It wakes up and licks it. You slowly start backing away toward the entrance bringing the cub with you. Your plan is to lure the cub away from its mother, then yell to wake up the mother and run out of the cave past the poachers. The mother bear will think the poachers are the ones that took her cub and hopefully take care of them. The cave tunnel is 500 meters long. Bears can run at 18 meters per second (~40 mph). You can run at 7 meters per second (~15 mph) but are leading the cub at 1 meter per second (~2 mph). The poachers are walking into the cave at 3 meters per second (~7 mph). How many seconds should you lead the cub before yelling so that you pass the poachers right when the bear gets to you and them?