You are taking care of two small children, Sarah and Rachel, who are twins. On a nice cool, clear day you decide to take them rollerblading. To travel down the smooth sidewalk you have Sarah hold your hand and Rachel's hand. The three of you form a straight line as you skate, and the two children just glide behind you. Sarah must reach up at an angle of 60 degrees to grasp your hand, but she grabs Rachel's hand horizontally. Since the children are twins, they are the same height and the same weight, 23 kg. To get started you accelerate at 2.0 m/s2 . You are concerned about the force on the children's arms, which might cause shoulder damage, so you calculate the force Sarah exerts on Rachel's arm, and the force you exert on Sarah's other arm. You assume that the frictional forces of the sidewalk on the rollerblades are negligible.