A ball of mass \( m \) is thrown vertically upward. Another ball of mass \( 2m \) is thrown at an angle \( \theta \) with the vertical. Both the balls stay in air for the same period of time. The ratio of the heights attained by the two balls respectively is \( {1}/{x} \). The value of \( x \) is _______.
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:
