An ant runs from an ant-hill in a straight line so that its velocity is inversely proportional to the distance from the center of the ant-hill. When the ant is at point A at a distance l1 =1m from the center of the ant-hill, its velocity v1 =2cm / s , what time will it take ant to run from point A to point B, which is at a distance l2= 2m from the center of the ant-hill?
