You are walking a dog when the dog sees a cat and runs away from you. You immediately run after the dog at 4.20 m/s. You jump at an angle of 28.0° to try and catch the dog. While you are in the air the dog is able to move an extra 1.57 m away from you. If you are able to land on the dog, how fast must the dog have been running if it was running at a constant speed in a straight line?