Range of a bob of mass $1\, kg$ is $80\,m$ while it attains maximum height $20\,m$. Its  change in momentum in complete motion ............ $N-s$

The position of a projectile launched from the origin at $t = 0$ is given by $\vec r = \left( {40\hat i + 50\hat j} \right)\,m$ at $t = 2\,s$. If the projectile was launched at an angle $\theta$ from the horizontal, then $\theta$ is (take $g = 10\, ms^{-2}$)

A cart is moving horizontally along a straight line with a constant speed of $30\,m / s$. A projectile is to be fired from the moving cart in such a way that it will retum to the cart (at the same point on cart) after the cart has moved $80\,m$. At what velocity (relative to the cart) must be projectile be fired? (Take $=10\,m / s ^2$ )

A particle is projected with an angle of projection $\theta$ to the horizontal line passing through the points $( P , Q )$ and $( Q , P )$ referred to horizontal and vertical axes (can be treated as $x$-axis and $y$-axis respectively).

The angle of projection can be given by

A body of mass $1\,kg$ is projected with velocity $50\,m / s$ at an angle of $30^{\circ}$ with the horizontal. At the highest point of its path a force $10\,N$ starts acting on body for $5\,s$ vertically upward besides gravitational force, what is horizontal range of the body? $\left(g=10\,m/s^2\right)$

A stone is just released from the window of a train moving along a horizontal straight track. The stone will hit the ground following