The resultant of two forces P and Q (such that P > Q) acting along the same straight line, but in opposite direction, is given by

The moment of inertia of a thin spherical shell of mass m and radius r, about its diameter is

If the gravitational acceleration at any place is doubled, then the weight of a body will be

The velocity ratio for the third system of pulleys is

The time of flight (t) of a projectile on a horizontal plane is given by