kinematics Questions

A bullet is fired from a gun at the speed of $280{\text{m s}}^{-1}$ in the direction $30^{\circ }$ above the horizontal. The maximum height attained by the bullet is ($g=9.8{\text{m s}}^{-2},\sin 30^{\circ }=0.5$):

A vehicle travels half the distance with speed $v$ and the remaining distance with speed $2v$. Its average speed is:

A bullet from a gun is fired on a rectangular wooden block with velocity $u$. When the bullet travels $24\text{cm}$ through the block, its velocity becomes $u/3$. It further penetrates into the block in the same direction before coming to rest at the other end. The total length of the block is:

A horizontal bridge is built across a river. A student standing on the bridge throws a small ball vertically upwards with a velocity $4{\text{m s}}^{-1}$. The ball strikes the water surface after $4\text{s}$. The height of the bridge above the water surface is ($g=10{\text{m s}}^{-2}$):