Projectile motion

A bullet is fired from a gun at the speed of \(280\,\mathrm{m\,s^{-1}}\) in the direction \(30^\circ\) above the horizontal. The maximum height attained by the bullet is \((g=9.8\,\mathrm{m\,s^{-2}},\ \sin30^\circ=0.5)\) :

A ball is projected with a velocity, \(10\ \text{ms}^{-1}\), at an angle of \(60°\) with the vertical direction. Its speed at the highest point of its trajectory will be :

A car starts from rest and accelerates at 5 m/s\(^2\). At t = 4 s, a ball is dropped out of a window by a person sitting in the car. What is the velocity and acceleration of the ball at t = 6 s ? (Take g = 10 m/s\(^2\))