Juku went sledging with his friends. When going back, two of Juku’s friends sat on his sledge and Juku tried to pull the sledge after him on a horizontal and snowy road. What is the minimal angle between the rope of the sledge and the ground so that it is possible for Juku to pull the sledge into motion? Juku’s mass is m1=\SI60kg and the coefficient of friction between Juku’s boots and the snow is μ1=\SI0.30. The mass of the sledge together with Juku’s friends is m2=\SI110kg and the coefficient of friction between the sledge and the snow is μ2=\SI0.20.