If a shell fired from a cannon explodes in mid-air,then which of the following is true?

$A$ train is moving along the tracks at a constant speed $u$. $A$ girl on the train throws a ball of mass $m$ straight ahead along the direction of motion of the train with speed $v$ with respect to herself. Then

Two beads $A$ and $B$ of masses $m_1$ and $m_2$ respectively are placed on a smooth vertical circular wire of radius $R$ as shown in the figure. Bead $A$ is given a very gentle push so that it slides down and collides with bead $B$ and comes to rest. After the collision,bead $B$ reaches the height of the center of the circle. Then $m_1 : m_2$ is equal to:

Two bodies of masses $0.1\, kg$ and $0.4\, kg$ move towards each other with the velocities $1\, m/s$ and $0.1\, m/s$ respectively. After collision they stick together. In $10\, s$,the combined mass travels ............ $m$.

$A$ particle is projected vertically upwards with a speed of $16 \ m/s$. After some time,when it again passes through the point of projection,its speed is found to be $8 \ m/s$. It is known that the work done by air resistance is the same during upward and downward motion. Then the maximum height attained by the particle is ...................... $m$ $(g = 10 \ m/s^2)$.

The mass of a person is $60 \, kg$. If he gains $10^5 \, \text{calories}$ of heat energy from food and the efficiency of his body is $28 \%$,then up to what height can he climb? (approximately) ($g = 9.8 \, m/s^2$,$J = 4.2 \, J/\text{cal}$)