The maximum speed of a boat in still water is \( 27 \, \text{km/h} \). Now this boat is moving downstream in a river flowing at \( 9 \, \text{km/h} \). A man in the boat throws a ball vertically upwards with speed of \( 10 \, \text{m/s} \). Range of the ball as observed by an observer at rest on the river bank, is ______ cm. (Take \( g = 10 \, \text{m/s}^2 \) )
A person travels \( x \) distance with velocity \( v_1 \) and then \( x \) distance with velocity \( v_2 \) in the same direction. The average velocity of the person is \( v \), then the relation between \( v \), \( v_1 \) and \( v_2 \) will be:
