The initial velocity of a particle of mass $2\,kg$ is $(4 \hat{ i }+4 \hat{ j })\,m / s$. A constant force of $-20 \hat{ j }\,N$ is applied on the particle. Initially, the particle was at $(0,0)$. Find the $x$-coordinate of the point where its $y$-coordinate is again zero.$..........\,m$

A ball is projected from ground with a speed of $20\,m / s$ at an angle of $45^{\circ}$ with horizontal. There is a wall of $25\,m$ height at a distance of $10\,m$ from the projection point. The ball will hit the wall at a height of $.........\,m$

A projectile is thrown with a velocity of $50\,\, ms^{^{-1}}$ at an angle of $53^o$ with the horizontal .Choose the incorrect statement

A projectile is projected with kinetic energy $K$. If it has the maximum possible horizontal range, then its kinetic energy at the highest point will be ......... $K$

A projectile is fired from the surface of the earth with a velocity of  $5 \,m s^{-1}$ and angle $\theta$ with the horizontal. Another projectile fired from another planet with a velocity of $3 \,m s^{-1}$ at the same angle follows a trajectory which is identical with the trajectory of the projectile fired from the earth. The value of the acceleration due to gravity on the planet is (in $\,m s^{-1}$) is 
(Given $g = 9.8 \,m s^{-2}$) 

For a projectile, the ratio of maximum height reached to the square of flight time is ($g = 10 ms^{-2}$)