Due to heavy winds a tree fell down in the middle of the road and the vehicles got stuck in the way. Two residents came forward to place it aside but could not accomplish it as they were too heavy. A passerby helped them with heavy blocks. They cleared the road and the traffic began to flow as usual. (i) Which value is shown by the passerby and the residents? (ii) Which energy is stored when the heavy log of the tree is lifted to some height?