1.} A balloon of mass M is moving down with an accelaration a. The mass of the balloon that must be detached so that it moves up with same accelaration is _________
2.} A shell moving horizontally explodes into 2 fragments. One of hte fragments immediately after explosion attains a momentum "p" vertically up and other fragment attains a momentum 
p in a direction inclined at arc{tan 1/
} below the horizontal. The momentum of the shell before explosion is _________
3.} A stone is projected upwith velocity u. it crosses a point at a height h in its path after times t1 &t2 from the instant of projection. Then t1 + t2 ; t1 t2 = __________
4.} A ball is proj at an angle 45 with the horizontal just crosses a wall at a distance 'a' and falls at a distance 'b' beyond the wall. then wall's height is _________
5.} A stone of mass 1kg. tied to a string of lenght 10/3 m and rotated in a vertical plane. I f the ratio of max. tension to min. tension is 4, then the speed of the stone at the highest point of circle is _________
6.}A particle is moving along a straight line A,B,C. Its velocity at A and C are 5m/s &25m/s resp. If BC=2AB, then the ratio of time of travel from A to B, to that from B to C is __________
7.} A constant force acts for 5s on a body of mass 4 quintals which is at rest and then siezes to act. During the next 5s, the body travels 400m. Then the magnitude of force is ___________
